New LS swap/install questions

[First c10]

Hello all,

I have a few questions regarding the swap.

1) When you start up the truck with the lsx motor is it normal that the idle is about 1000-1200 for a few seconds and then is slowly drops to about 600?

2) When I put the truck in reverse the engine revs up a little is this normal?

I just completed the 2-1/2" Stainless exhaust with flowmaster clones and really got to drive the truck for the first time rather than just starting it up and backing out or pulling it in the shop.

3) Does the truck computer need to learn to dial these issues in?

oh and

4) When I step on the brake and come to a stop it feels like the TC is still locked for just a second because the rpm drops to about 350 and than it releases and goes back to about 600?

2011 Chevy 1500 LTZ with 5.3 LC9- 6L80E

Thanks for the help !!!!