Sounds like you have housing under control. Most of the info I have is from breeders; I've only kept my one retic for about a year to date. As for mixing a male and a female that should be no problem, especially before sexual maturation. The only time my retic bit me was after I handled another male and didn't wash between (as many times as I've been warned: I wasn't thinking and mine isn't sexually mature.) When I've seen mature males put into mature females cages the female quickly emptied some of her cloaca and waved her tail about; my guess (and the breeders) is that the female doesn't want to be mistaken for a male.
I started mine in a Jumbo Reptile Keeper (TOM/Oscar) for a very short bit, then switched him to a 322 Vision (36" W x 23" D x 21" H.) I just got in his 632 Vision (72" W x 36" D x 18" H) he'll go in this weekend.
I bought him from NERD at Daytona last year; he measures in between seven and eight feet. I have over a dozen other boids and I've never seen a snake grow like this, or with such a voracious appetite! I'm happy I got into Retics- great personalities. He'll follow me around the house and watch what I'm doing (he and my dog, always supervised, ignore one another. My dog grew up with reptiles running around the house.) I'll be getting a female super tiger soon. I've worked with the females at demos. Awe inspiring. And I saw one of Prehistoric's tiger females. The morph was even more impressive for me.
I'm sure some of the long time retic keepers have a bunch of great advice for you as well.
Cheers!