... Flower Saver?

No no no, you HAVE to have Heart Finder to make everything work.

I would say you could get by without it, but it's definitely risky.  Especially since it probably means you don't have the Star Pieces for Item Hog either.

Flower Saver just isn't worth 10 of your limited 15 star pieces for this run. You have a bunch of Sweet Treats, you hardly miss Flower Saver.

Here is the ideal combos in a Pre-Hook Pit Run for maximum level ups (information used to calculate is from jdaster64)
Floor   Most Star Point Combo
1   Gloomba, Dull Bones - Let Dull Bones clone
2   Spinia,Spania,Spinia,Spania,Spinia
3   4 Spanias or Spania,Fuzzy,Spania,Fuzzy
4   4 Dull Bones - Let Dull Bones clone
5   5 Fuzzies
6   Gloomba, Dull Bones - Let Dull Bones clone
7   Spinia,Spania,Spinia,Spania,Spinia
8   4 Spanias or Spania,Fuzzy,Spania,Fuzzy
9   4 Dull Bones - Let Dull Bones clone
11   Paragoomba, 2 Pokeys - Let the Pokeys clone
12   4 Clefts
13   P0key, Pider, Pokey, Pider - Let the Pokeys clone
14   Dark Puff, Pokey, Dark Puff - Let the Pokeys clone
15   2 Piders, 2 Pokeys - Let the Pokeys clone
16   Paragoomba, 2 Pokeys - Let the Pokeys clone
17   4 Clefts
18   P0key, Pider, Pider, Pokey - Let the Pokeys clone
19   Dark Puff, Pokey, Dark Puff - Let the Pokeys clone
21   2 Spiky Gloombas, 2 Boos
22   Bandit, Boo, Bandit, Boo, Bandit
23   2 Lakitus, 2 Bob-ombs - Let the Lakitus toss Spiny Eggs
24   2 Bob-ombs, 2 Boos
25   4 Boos
26   2 Spiky Gloombas, 2 Boos
27   Bandit, Boo, Bandit, Boo, Bandit
28   2 Lakitus, 2 Bob-ombs - Let the Lakitus toss Spiny Eggs
29   2 Bob-ombs, 2 Boos
31   1 Dark Koopa, 2 Parabuzzies
32   2 Hyper Clefts, 1 Parabuzzy
33   4 Parabuzzies
34   4 Shady Koopas
35   5 Flower Fuzzies
36   1 Dark Koopa, 2 Parabuzzies
37   2 Hyper Clefts, 1 Parabuzzy
38   4 Parabuzzies
39   4 Shady Koopas
41   4 Dark Paratroopas
42   1 Bulky Bob-omb, 1 Poison Pokey, 1 Spiky Parabuzzy - Let Poison Pokey clone
43   2 Lava Bubbles, 1 Poison Pokey, 1 Bulky Bob-omb -Fire Drive the Lava Bubbles
44   2 Poison Pokeys, 2 Spiky Parabuzzies - Let Poison Pokey clone
45   2 Spiky Parabuzzies, 2 Lava Bubbles -Fire Drive the Lava Bubbles
46   4 Dark Paratroopas
47   1 Bulky Bob-omb, 1 Poison Pokey, 1 Spiky Parabuzzy - Let Poison Pokey clone
48   2 Lava Bubbles, 1 Poison Pokey, 1 Bulky Bob-omb -Fire Drive the Lava Bubbles
49   2 Poison Pokeys, 2 Spiky Parabuzzies - Let Poison Pokey clone
51   2 Badge Bandits, 1 Ice Puff
52   4 Ice Puffs
53   4 Dark Boos
54   1 Red Chomp, 2 Ice Puffs
55   4 Moon Clefts
56   2 Badge Bandits, 1 Ice Puff
57   4 Ice Puffs
58   4 Dark Boos
59   1 Red Chomp, 2 Ice Puffs
61   2 Dark Lakitus, 1 Dark Craw - Let Dark Lakitu toss Sky Blue Spiny Eggs
62   4 Dry Bones - Let the Dry Bones clone
63   1 Dark Wizzerd; 2 Dry Bones - Let the Dry Bones clone
64   1 Frost Piranha, 2 Dark Lakitus - Let Dark Lakitu toss Sky Blue Spiny Eggs
65   1 Dark Craw, 1 Dark Lakitu - Let Dark Lakitu toss Sky Blue Spiny Eggs
66   2 Dark Lakitus, 1 Dark Craw - Let Dark Lakitu toss Sky Blue Spiny Eggs
67   4 Dry Bones - Let the Dry Bones clone
68   1 Dark Wizzerd; 2 Dry Bones - Let the Dry Bones clone
69   1 Frost Piranha; 2 Dark Lakitus - Let Dark Lakitu toss Sky Blue Spiny Eggs
71   1 Wizzerd, 2 Chain Chomps
72   1 Dark Koopatrol, 2 Chain Chomps
73   5 Phantom Embers - Fire Drive the Phantom Embers
74   2 Swoopulas, 2 Wizzerds/2 Dark Koopatrols
75   4 Chain Chomps
76   1 Wizzerd, 2 Chain Chomps
77   1 Dark Koopatrol, 2 Chain Chomps
78   5 Phantom Embers - Fire Drive the Phantom Embers
79   2 Swoopulas, 2 Wizzerds/2 Dark Koopatrols
81   5 Spunias
82   1 Dark Bristle, 3 Arantulas
83   4 Arantulas
84   1 Piranha Plant, 3 Spunias OR 4 Piranha Plants
85   5 Spunias
86   5 Spunias
87   1 Dark Bristle, 3 Arantulas
88   4 Arantulas
89   1 Piranha Plant, 3 Spunias OR 4 Piranha Plants
91   5 Elite Wizzerds
92   2 Poison Puff, 1 Swampire, 1 Amazy Dayzee
93   3 Bob-ulks, 1 Amazy Dayzee
94   1 Swampire, 1 Elite Wizzerd, 2 Amazy Dayzees
95   5 Elite Wizzerds
96   2 Poison Puff, 1 Swampire, 1 Amazy Dayzee
97   3 Bob-ulks, 1 Amazy Dayzee
98   1 Swampire, 1 Elite Wizzerd, 2 Amazy Dayzees
99   5 Elite Wizzerds

Sounds like you're going to have a rough time regardless if you're going to do it without Mega Rush P. But, the Power Plus should come in handy for extra powerful Fire Drives. It won't help too much for Power Bounces.

FP Drain on Bonetail isn't a bad idea, though, you're taking an inherently longer battle in the name of keeping FP high. Add Happy Flower and Pity Flower, and you should be able to have at least 2FP for nearly every turn. On the other hand, without FP Drain and with Power Plus, you can do 1 damage with a normal hammer attack, and get a stylish for more SP.

Well, just finished the run, and on my first try! I did end up bringing in a handful of items, but I only ended up using one POW Block outside of what I got in the Pit.

Some various thoughts:
- Mega Rush P was hardly missed, no joke. It made the 20s considerably harder, though (which were incidentally the site of my only two failed runs to date). Pretty much any enemies that I would have used it on ended up being bearable anyway.
- Heart Finder was sorely missed in the 60s for bringing back partners; that set of floors was far and away the hardest without partners to help me grind out harder battles.
- Item Hog and Pretty Lucky #2 were missed anout as much as Attack FX Y. Don't kniw if the drop rate was unusually high or what, but I never ended up short on items, and was very conservative with what I did have. Likewise, I never really needed an evasion boost.
- I forgot to use FP Drain, so I don't know how the final fight would have gone with it.
- Power Plus was just sick; being able to do 2-2 jumps and 6-power Fire Drives was completely invaluable throughout the run.
- Average luck with enemy sets, but they had a TON of held items. Nothing terribly debilitating; but the two sets of Elite Wizzerds had four or five items between them.
- No Fright Masks used, only three or four Movers, but obviously no Amazy kills, so I ended up at a reasonable level 23 this time.
- The 60s were absolutely hideous, with a ton of fighting at 10-15 Mario HP; conversely, the 80s and 90s went absolutely perfectly. I Superguarded roughly 30% of Mario hits by Dark Craws, but upwards of 80% on all of the 80s (I think I had a run of twelve superguards on Dark Bristles alone).
- Two Last Stands P = win. I kept Goombella alive tons longer than I would have otherwise.

The run went really great overall, much better than the one I have on my YouTube channel. Considering doing some live commentary, but I don't know. Three and a half hours+ of commentary could get repetitive pretty fast.

Whenever I do finish the videos, at any rate, I'm planning on posting my "Pit of 100 Trials Enemy Guide" that I had handy along with them.  I'm trying to decide if I should make a little reference sheet for Star Power as well; there's only a couple of formulas for Star Power gain, and both are really easy to calculate on the fly (assuming you can estimate square roots reasonably well; even if you can't, the first digit is enough to go off of).

Also, watching floor 98 of my run again gave me a great idea for a video I should post separately in the meantime.  All I can say is that it involves status effect weaknesses.

I see you grinded up max coins to pay for items to take care of enemies that can easily become Superguard-only.

Which is fine, but I always felt the point of a Pre-Hooktail was to show how you don't have to do any grinding to do this challenge.

(I'm only going to watch parts of the 70s onward)

I was going to say you beefed up FP too much (obviously you have to beef up HP), but I see deep in the Pit, especially in the 80s, you have to have your extra partner take some hits for you just because Mario was going to die otherwise, so more Fire Drives are needed.

You didn't even use luck badges at all except for Bonetail? Dang son.