question about the gentitive case...

[costumier.livejournal.com]

hello to all.

I'm trying to learn the genitive case, and I was wondering how one would write "______ of (foreign name here)." I'm very new to all this, so bear with me...
----------------------------------------
**FEMININE Names:
Russian: of Юля = Юли? or Юляи?

Foreign: of Кайли(Kylie) = Кайли-?

**MASCULINE Names:
Russian: of Борис = Борися?
-->"Саша" is a masculine name; and the genitive endings for masculine nouns are "-a" and "-я"; yet "of Саша" is written "Саши", right? Why?

Foreign: of Роберт(Robert) = Роберт-?
----------------------------------------
Upfront apology for any mistakes...

THANKS FOR ANY HELP! :-)

Two related questions about gender.

[kutsuwamushi.livejournal.com]

This was kicked off by the last post.

1. In linguistics, nouns are said to have natural or grammatical gender (this is not an exclusive "or"). Natural gender refers to the actual sex of the object, and grammatical gender refers to the class of a noun. What grammatical gender are words like папа? They are declined like feminine nouns, but given masculine modifiers. And is there a term for this?

2. Are there any instances where nouns that are naturally feminine appear masculine? I've only seen it the other way around.

[Edit] Thank you for all your quick responses!