In football, if a player forces the ballcarrier out of bounds, is it conaidered a tackle?

yes

well, it really depends on the situation, actually. if he is tackled out of bounds (brought into the ground out of bounds), yes. if he's pushed (and forced) out, yes. if he runs out while someone's trying to tackle him and fails, then no.

in most cases, yes.

Yes. This is true because a tackle is when a player on the offense is forced down or out of bounds, or when your knee(s) touch the the ground because of another player.

N-o

no tackle is recorded when a player is forced out of bounds

this is why on gamecasts/box scores it would read

Pass complete short to Ryan Grice-Mullen, forced OB at Boise State 41.

Yes.