Get rid of prerequisite chains

Long prerequisite chains suck. They suck bad. Why should I have to take 1-4 feats/enhancements/epic destiny abilities/reaper enhancements that I don't want, just to reach the one I *do* want? It limits build choice.

You want examples? Have I got examples for you!

Handwrap monks almost all take the exact same 10 heroic feats, 6 of which are prerequisites.
Greater two weapon fighting and its 2 prerequisites, whirlwind attack and its 4(!) prerequisites, stunning fist, and improved critical. The twf feats aren't *too* bad, as they are useful when you get them, but each overwrites the previous one.
Whirlwind is just egregious. Until the recent change to spring attack, I would not choose to take *any* of its prerequisites if I didn't need them for whirlwind. They all give very marginal benefits that I can live without.

Most other melees take 3 weapon style feats, when each just overwrites the previous feats.

Energy burst. It's a great t4 twist on any int/cha caster. However, if you're in draconic, it costs 9 epic destiny points to max it out.

Master of [spell school] in magister costs 12(!) points to max out

Sorcerer savant SLAs cost 9 ap to max out.

Efficient heighten costs 8-12 ap to max.

Lightning motes sla from artificer arcanotechnician takes 12 ap.

All enhancement tree cores require the previous cores.

In most cases, some or all of the prerequisites are taken only to reach the end of the chain, or players avoid the chain altogether because it's too expensive.

I guess I read these differently as I don't see them as overriding but enhancing

Lets take Two weapon fighting and its chain

TWF - Reduces the attack penalty and grants 40% off-hand
ITWF - Increases the off-hand +20% to now 60%
GTWF - Increase the off-hand +20% to now 80%

So without the TWF you wouldn't have the reduced penalty or +40%, ITWF and GTWF only grant +20% off-hand. So why wouldn't you want the other two if you want GTWF?

In general all feat chains are fine.
Even whirlwind that requires: Dodge, mobility, spring, combat expertise is okay.
Dodge, mobility are pretty good feats giving you Dodge! Spring is an amazing feat by it self.
Now combat expertise is the only feat I'm not using as I prefer power attack. But I think if you need to tank is pretty okay too.

Moreover, the feat chains come from D&D and are pretty standard, if you break them it would really be a mess.

I thought this was going to be about quests being chained, which I'd be much more behind :)

Feat chains make sense. Otherwise everyone would just take the "capstone" feats and that'd be both homogenizing and kinda OP. People complain about Dodge/Mob being required for SA now, since Dodge on gear is so plentiful...but Mob gives you +2 to your MDB, which means for anyone that's not in Cloth armor that's +2 Max Dodge in practice. So 3 feats for SA and +2 Dodge isnt that bad. Plus if you're Kensei or Tempest (and a lot of builds are) that unlocks even more MDB and Dodge Cap in T3.

The only legit complaint is removing Combat Expertise from the WW prereq. It serves no purpose other than to eat a feat and give Monks an otherwise useless INT prereq that especially hurts newer players with no INT tome.

I agree with you for the Whirlwind feat line, but not TW/HF. The Style feats are fine, though in general, I would prefer they just scale rather than having to take them.

Dodge/Mobility/Spring Attack/ Combat Expertise are all not very useful. Mainly because dodge caps out, so stacking a bunch isn't useful for most classes that have very little dodge uncapping abilities like Monk has. It's the longest single feat line and has been a bane to players here and in tabletop. In tabletop (pathfinder), I use house rules to collapse Dodge/mobility into one feat and all of the tradeoff mode feats (Combat Expertise, Power Attack, etc) are free. It seems to me that that would work here. Power Attack and Combat Expertise join Defensive fighting as free feats, Dodge and Mobility just becomes Mobility, which makes the feat line now Mobility, Spring Attack, Whirlwind Attack. Much easier to take now.

With the enhancement ones you mentioned, I agree with most of what you say. With long enhancement chains, you end up spending a lot of AP on stuff you don't really need, which prevents other cool things to be taken. But they are there because it is a progression of abilities. The only one I think reeeeeaaaaally needs changing is metamagics. They a) should not cost 2 ap a rank and b) to get heighten in most metamagic enhancement lines, thats 6 AP for one, 6 for the other, and 4 more. 14 AP for 40% cheaper metamagics. So many points for the most boring enhancement line in existence, yet almost needed to help SP burn. For these though, it isn't the length of the chain that is the problem, but the cost per rank.