You are correct in both cases! V channel is used by squads,they will all tune the same channel,say 123 and their comms will be only heard by those tuned.
As for text you have several options,country,anyone on your country can read the text. You have room which alls you to talk to only those who upped from the same base as you to see. Then you could select all channel,if the arena supports this and well all players can see this,or use 200 which many players use instead of all channel,channel 1.
Then there`s also range vox,default F12 which allows you to talk to anyone on your team that is within icon range or roughly 6k distance.
Hope that helps,any more question just keep asking...

PS: sorry Dot should have read you answer,was better than mine....
