whether fine if I delete received game, which was removed from Steam?

As long as you don't mark the giveaway non received... What you do is up to you, but you have to accept the consequences if someone reports you, though I doubt the mods will care since it's an old giveaway.

what about sgtools ?
why enter ga for the game you do not want ?

1. Don't enter for games you don't want (I'll just get that out of the way up front).
2. If you delete it, you'll be flagged with an unactivated win.
3. If #2 is fine with you, then go ahead and delete it.
4. Expect people to check your profile now that you've posted about it.
5. Expect subsequent suspension.

:X

is there any reason you'd want to delete a game from your account to begin with?

Long story short . DONT Remove any game you won here from your account , even if its garbage like that .

Also Dont just hoard games for the +1 , enter for stuff you actually want to play / own .

There may have been that poor soul out there , who really wanted that game and you took the chance away from him just for +1 in your library .

Thx for answers