Feat swap guidance needed

[EKKM]

Hi all,
I currently have a rogue 7, ranger 1 - favoured enemy undead
Feats: TWF, TWF defence, SF search, wpn finesse
Enhancements: Way of the mechanic line, dexterity, wpn speed boost

I took the ranger level to add martial weapons, keep my skills up and gain some usefullness agaist undead.

I also planned on taking a second level of ranger to gain the two weapon fighting feat. I would then use the flawed dragon shard I have to swap TWF for something else.

2 questions:
1- Is that allowed. I was concerned (after taking the first ranger level) that I would not be allowed to switch out the TWF feat I took at lvl 1 as it was required as a prereq for TWF defence when I took that at level 6.

2- What feat should I take if I am allowed? I was leaning towards Iron will as my will save stinks and I am tired of getting held, danced, hypnoed etc.

[Hvymetal]

My understanding you are looking at two feat swaps here, 1st you would have to swap out Two Weapon Defence as that feat relies upon TWF as a Pre-Req. Then you would be able to swap out TWF. Iron Will is not really a bad choice, but what's your CHA? Force of Personality might be a better choice? I ahve't leveled since update so haven't checked it out yet.

[EKKM]

My charisma and wisdom are both a base of 10 so force of personality is out. Its a 28 pt build so most points went to DEX and INT with the leftovers to CON (all stats area are at least 10).

Would I need to do the double swap if I took the ranger level prior to swapping the feats? At that point I would effectivelty have the TWF feat twice. As that would be a bit of a waste I probably wont take a second level of ranger.

[Hvymetal]

My charisma and wisdom are both a base of 10 so force of personality is out. Its a 28 pt build so most points went to DEX and INT with the leftovers to CON (all stats area are at least 10).

Would I need to do the double swap if I took the ranger level prior to swapping the feats? At that point I would effectivelty have the TWF feat twice. As that would be a bit of a waste I probably wont take a second level of ranger. That unfortunatly I could not answer for you, sorry.

[MysticRhythms]

Two-Weapon Defense is pretty weak anyway. Dodge is strictly better and in all honesty, +1 AC isn't worth a feat on a character that won't have a lot of bonus feats.

Iron Will isn't a bad choice. Neither is something like Skill Focus(UMD).