Rugs, Carpets and Carpeting - padding

We bought a house. We tore out the nasty old carpet and we are ready to carpet my daughter's bedroom. We might do it ourselves. We have new carpet that is plush solid color ( no pattern) and the room is rectangle and would need no seams. Most of the old tack strip seems to be good. My question is would 6 lb padding be right.?Also, do you lay the padding right up next to the tack strip. What tools would we need to rent besides a stretcher? Any advice would be appreciated.

Rent a knee kicker and a pole stretcher.

6-lb. pad is fine, as long as it is no thicker then 7/16". 8-lb., 7/16" would be better.

What kind of flooring is outside the bedroom at the doorway? More carpet? Tile? Wood? Laminate? Vinyl?
How do you plan to finish off the transition.

Her bedroom connects to a hallway. This hallway connects all the bedrooms. It will eventually have a western spice berber on it, that will be professionally installed. This is because that same carpet will go down steps, cover a landing, and do another room. Much to tricky for us . This won't be done until later after the bedrooms are done and the hall is painted. Her floor is made of wood 2 X 12 planks with 1/2 inch particle board over them.. Is it ok to use the old tack strip? Do we put the padding right up to it. We have small children and we thought the thicker the pad the better. Are we mistaken? Thanks again.

Thicker then 7/16" padding will void all manufacturers warranties on the carpet. It will cause wrinkles to appear quicker, and cause premature delamination of the backings.

Yes, it is ok to use the old tackstrip, as long as it is the right distance from the wall/baseboards and has not been pet damaged or water damaged.

Your going to have to do something at the transition, till the new berber carpet is installed in the hallway!

Just trying to see if I can post this question.