First off, I'm a little afraid of some of the abilities some pokemon now have.
These are the main ones I think can be scary. Slaking with Pure Power is extremely terrifying; Norman will be almost impossible without overleveling. Tauros & Heracross are right behind it in terms of being completely overpowered. The others are mainly just exceedingly powerful.
I'll just make some personal suggestions. Not saying you have to follow them, but I figure I might as well say what I'd think would be cool to have in the game:
Give Ancientpower the treatment you gave Silver Wind; I realize that Rock Slide exists, and Bugs don't have the luxury of having too many good moves. But still... you could give it 15 pp, or 65-70 power.
Make the move Bounce more accurate or give it more pp; as is it's nearly unusable. 100 accuracy with 5-10 pp, or 90 accuracy with 10-15 would be nice.
This is more irrelevant but make Twineedle a base 35-45 move; only Beedrill knows it, but it gives it a good boost.
Make the fossil pokemon evolve sooner. It's a pain to have to get them all to 40 and not be all that amazing. Make them evolve at 25 or 30.
Shedinja- It could be just my rom, but Sheinja still has just 1 HP. IMO, If you wanna make it usable, you'll need to either give it some HP, or leave the HP as is and focus on it's speed, Attack, and Special Attack stats, abandoning it's Defense and Special Defense entirely. A better moveset would help as well
Maybe add better items in random locations. I understand giving items to gym leaders when you have no access to them makes the game way harder; but I think giving us a few of the better items as the game goes on would be interesting; finding something awesome like Leftovers in a Dive area, or in Victory Road would be awesome.
(You could put more of the move tutor moves you'd only get in the Battle Frontier in random places; Body Slam, Swords Dance, Rock Slide, elemental punches, etc. aren't so powerful that it would be unfair to place them somewhere before you beat the Elite Four)
And I know I said a lot, but again, this hack is awesome :)
Thanks, I appreciate the feedback!
This list of abilities was from a few months back and when I actually looked at the abilities on the ROM I realised that none had been edited, so I went over them and I, myself noticed some seemed slightly unreasonable. I've been wary of the abilities since releasing them including a couple of the ones you've highlighted which is why I might need to re tweak and change/remove some of these abilities as I've had a few people commenting on them. However, I did change a couple since that list is slighty outdated. Slaking no longer has Pure Power but remains with it's original ability as Truant to give people a chance rather than getting demolished by Norman who is already tough, Dodrio now has Huge Power and the reason for this is to maxmise the potential of it's high Attack stat of 120 to make battles with those who use it such as Archie, Winona etc more difficult.
For the Magnemite line, I figured giving it an extra ability being Levitate it would make it more of a threat since I did want to up the difficulty of this hack, by doing this assuming you're battling a Magneton with the Levitate ability the x4 weakness to Ground is removed. I think the Speed Boost suits Tauros with it having a high Speed stat to give it that extra boost when battling Pokemon that usually outspeed it, Pure Power isn't really necessary in this case I'll admit. I have already substituted Heracross' Pure Power with CompoundEyes since it seemed more fitting for it. Milotic having Drizzle also seemed reasonable in my opinion since it can learn a great deal of Water Type moves and since when in Raining conditions, water type moves are boosted and Houndoom has Intimidate rather than Drought for obvious reasons.
I'll take suggestions on what could be substituted for the current list of Abilities if they seem too off the scale and I will also take any new submissions that could be applied to other Pokemon.
Also levitate magnemite line just plain godmods it. But so do many other side ability changes.
There are a few Abilities that have been changed but I'll be working on some more throughout the week to balance it out.