im using a filco tenkeyless..  cherry mx browns.

i never tried using the lift up feet. i dont have a prefrence yet

Stiffer? 
Probably the way you press down the keys is straight down instead of pushing slanting forward (angle) which explain the switches being stiff due to switches stem is rubbing the housing.
Well, I could be wrong...   

What about these?

https://heavy-arm.com/en/118-mechanical-keyboard-accessories

I've no idea where to buy keycaps i only saw this one available

Then i think i'll stick with the filco original first then 

Where can i find keycaps though? Garage sales seems pretty meh..

May I know what programming language you use for coding purpose?

I'm not sure what kind of answers you are looking for.

About HHKB part:

For programming:
- Don't use fuctional keys like F1-12
- Most of the time touch typing (lazy fingers)
- using arrow keys are bad habit if you are using VIM (so, arrows keys redundant too)
F1-12, arrow keys, page up down etc all become redundants for some programmers.
Hence, 60% keyboard is a good choice.

Smaller, compact with lesser redundancy.

Of course, arrows keys are very important if you using a lot of different software and apps in your OS.
TKL is more universal, much better in my opinion.

Advice: Don't buy something you want but you don't need to impress others.

60% layout is actually quite good especially when you're taking keyboard to office. Might takes time to get use to it though.
Currently using 65% layout, but have been ditching my arrow keys since using fn + wasd for navigation is much better as I dont have to move my right hand.
As for f1-f12 keys, depending on development apps you're using. If basic software like vim, gedit, notepad++, dont really need those.

razer mostly is blue.

ss mostly is black/red