Two questions!
One, on average how long do you have between deaths if your an active player who seeks out enemies and joins in on the battle?
And number two, how close to enemies or friendlies do you respawn? or just where?

Sorry about the second and. I didn't notice it until it was to late!

First one will depend on map and play style, so I can't answer that.
You spawn at an established command post.

There's a timer counting down and whenever it hits 0, every dead teammember respawns. (Wave respawn)
Standard respawn time depends on map, team (Defending team might get extra respawn time to balance the game), bonuses. It will be around 20-30 seconds.
Bonuses include capturing command posts.

You respawn with all teammates at a certain spawnpoint. These spawnpoints switch when the attacking team completes certain objectives. You generally spawn pretty close to the action.

If you engage the enemies a lot you will probably die a lot.


In the first stage of Container City, you will be almost right in the battle after you respawn.

The Security spawns on the gangplank and only has to walk straight forward towards the gate they have to blow up.
The Resistance spawns a little behind said gate and has a straight alley leading them right towards the hot zone.

20-30 seconds seems like a long time until a respawn.

Your respawn won't always take that long, for example lets say the respawn timer is 25 seconds. That timer will be counting during the whole game over and over again. If you die near the start of the counter you will have to wait longer to respawn than someone who dies towards the end.
Basically everyone will respawn at the same time in waves every 25 seconds.

You have medics that can revive you. So those 20-30 seconds will be a wait for a Medic.

It's needed to make the attacking team able to complete certain objectives.
+ what the others already said.