Also, I figured I'd give you some more general advice on a couple of the questions...
Specifically, pet names. These are different for every guy, just as I'm sure yours isn't the same as other women's. The one that's pretty consistent, though, is 'boy'. Especially praising, 'good boy!' or scolding 'bad boy...'. I've never met a single male submissive who didn't love that and feel their hearts flutter every single time.
That said... as the relationship develops, ask him what he likes to be called while he's subbing. And if you
really want him to feel special, take the time to think up a new, original, uniquely fitting pet name for him. He'll be thrilled, trust me. Guys are sentimental too, we just don't wear it on our sleeves as much.
As for being dominated by someone who's normally a submissive? I've never met a sub who would be bothered by that in the slightest. At the very worst, it might disappoint someone looking for really extreme domination, but that isn't honestly what most subs want anyway.
Rather, a former (or current sub/switch) choosing to try to dom for me has several huge advantages already going for them.
First, they have experience being the sub. This is critical! Actually, the training master who owned me for a couple of months in my twenties talked a lot about that, and it may surprise you to know that when a dom is trained by another training master, it isn't by dominating a submissive in front of them... it's by
going through slave training himself/herself. Let that sink in a minute...
The serious, hardcore end of the BDSM community asserts that the single non-negotiable
key to learning to be a good, recognized, respected master is to learn to submit so you know what you're doing. You already have that!
Second, you're willing! That's huge! He
will appreciate that, I promise!
And finally, you'll have an easier time than most delineating a clear difference between play time and normal time. You'll be able to take off your 'domme hat' and put your 'normal person' hat on all the more easily because it's a conscious effort for you to domme.
There are, of course, disadvantages... but I'm sure those are already weighing heavily on your mind, so I won't belabor them.
Seriously, give it a shot! He'll appreciate it! Worst case, you're not intense enough for him or comfortable going as far as he wants... or you find that it ends up exhausting you and burning you out, and at least you know, and can either tone it back to a smaller part of your lives, or move on and find someone more right for you.