Whatever/whenever/whoever/whichever/however

Hello Teachers,

1. I will give the pen back to Renu or Reshama; ------------- it beloNgs to.(whomever/whoever)

'whoever' would be the more natural choice for speaking. "{whom} now sounds pretentious in most spoken contexts." [S Pinker: The Language Instinct]

I will give the pen back to whoever it belongs to, [either] Renu or Reshama.

2. Learn ---------- poem you find more interesting.(whichever). DYNAMITE

3. I will come -------------I can and I will bring ----------- you like with me. DEAD ON(whenever,whatever)

4. -------- hard I worked, she was not satisfied.(however). SPOT ON [a wee bit of BrE]

5. We [are] were warmly welcomed -------- we went.(whenever). BULLSEYE [on the ---ever part]

6. Take this bag, basket or ----------- it is and hang it up ------------ you find room for it.

(whatever, whenEver). For the 2nd part, probably 'wherever' would be better, Hanuman.

My choices are in the bracket.

Are they correct?

So far I feel some sentences are awkward [so far I feel].
Could you please correct [it] whatever you feel is so?