please help

I have three questions on three topics .please answer

Can we use noun clauses after all transitive verbs as a direct and as an indirect objects . Are these sentence correct??
A. I will buy what I want.
B.I eat what I want to eat.
I
C. I will give this to whoever runs fast.
D. I will give whoever runs fast this. (This is incorrect right?)

And also we can use noun clauses especially with noun+preposition and adjective+preposition combinations, do we need to remember the list of these combinations to use noun clauses or we can use it with preposition whenever.

That clauses
Are that clauses a part of noun clauses or it is different? If yes can we use that clauses as a subject of a verb and as an object of preposition just like noun clauses because I have never seen this. Could you give me some examples?

Gerund

It is said that if there is a verb after preposition that is gerund. Can we gerunds after all prepositions like with prepositions of place ,time?? I saw that there are noun + preposition ,adjectives +preposition to use gerund.do we need to remember these lists to use gerunds Or we can use it with all preposition whenever no need to remember? Are these sentences correct?
A. I don't want to argue about going to party.
B.I am curious about seeing it.

Possessive gerund
Can we use it after all transitive verbs as a direct object after all prepositions. Or again do we need to remember the list of verbs that takes possessive gerunds and combinations with preposition that take possessive gerunds. Are these sentences correct?
A.what is your reaction to his/him saying that.
B. I am taking about his/him arguing with me .
C. I am sorry for me/my not helping you.
D. I can't win this game without you/your supporting me.