Whole wheat oven baking temps

Hi There!

New to the forum here, but I have searched here many times and have found HUGE amounts of useful information! I had a question regarding the appropriate baking temps for whole wheat (lean dough) rustic style bread.

Anybody have any suggestions? How hot is too hot - how cool is not enough?

Also, how would the baking temperature affect oven spring.

Any feelings on adding vital wheat gluten in order to get a more open crumb (by enhacing gluten development)? I really like a chewy crust with a nice open crumb. (I read on the forums somewhere that leaving the oven door open so that the loaf (free form) dries out will give the crumb a nice shine - thoughts on that as well would eb appreciated.

Hope I am not asking for too much info in one sittiing here.

Thanks a ton!