Well... I would say: experiment!
I used to exercise with weights every day... because I was a damn maniac! I just loved challanging myself, and push myself. And by that feel strong mentally.
But I'm not that (irrationally) motivated nowadays, so it's more exciting to just exercise 2-3 times a week -- but very hard!
And exercise the whole body at once to stimulate your endocrine system (to make it produce more testosterone and growth-hormone).
Also experiment with what kind of exercises you do -- I'm certain that you can find a way to double the fun and muscle growth and weight loss.
And it should be commonsense that the body needs more rest...
After all: muscles aren't built in the gym -- they are built while resting.
And if your goal is weight loss, know that more muscle burns more calories/fat.