Female Animations and Hands in Main Game (Leon replacement)

Hi and yes, you are right, RE4 UHD modding is much harder because of fragmented and repetitive files organization.

Animations:
Don't replace all the FCV files at once, because their order may be different for Ada and Leon. If you say that left and right turn make the character move forward it means that you've replaced turn animation with the walking one.
My advice is to look through this list z6.invisionfree.com/Resident_Evil_4_PC/index.php?showtopic=796 it's for the old 2007 version of the game, but it can still be useful at finding the particular .fcv files.

Hands:
Replacing hands is a real nightmare in UHD.
You will need to check 4 places to completely replace the hands:
1) Unarmed hands + left hands. These hands are stored right in plXX.udas files. If we talking about pl00 Leon then it's the bin files starting with pl00_014.bin and eding with pl00_021.bin. These are mostly left hands for each weapon possible, but there is some few right hands as well.

2) Right hands that hold the weapon are stored in wepXX.udas files. If we talking about leon's hand that is holding his handgun then it's wep02_06.bin. So you need to put ada's right hands in all the wepXX.udas files that have Leon's right hands.

3) Inventory hands. No freaking idea why it was needed to store them separately but they can be found in "BIO4\SS\cmn\" folder, they are in ss_wepXX.dat files. .dat extracting\repacking process is the same as .udas. Also, wepXX.udas corresponds to ss_wepXX.dat, which is convenient. (By the way, you can find the inventory idle animation inside of these ss_wep files as well.)

4) (Optional) Cutscenes hands. This is one single model of fully rigged hands that is situated in Evd files (In EACH cutscene evd file!!! which is god damn strange). If we are talking about Leon then it is "YOUR_UNPACKED_EVD_FILE_FOLDER\event\model\ev0000\ev0003.bin". In Ada's case it's "YOUR_UNPACKED_EVD_FILE_FOLDER\em\pl02\pl020a.bin", but the body is there too along with the rigged hands.

I'm still looking for someone(aka as far as im concerned,3getu841 is working on ashley animations,She didn't even do them until i requested them xd) (I just wonder if its possible to edit files and MAKE ashley's physics joint become leons)

I can see only ADA TMP wep39.dat in that list.
I'm afraid that you will have to locate a lot of FCV manually. Just take one FCV that you know and replace some unknown FCVs with it until you will find it. Trial and error, you know.