Sounds like you're pretty spot-on with what you're doing. Just two things I'll address.
Partial range is never ideal, so see if you can get some help with this. Personally, I don't know what to tell you, but others on here are more knowledgeable in this area, and may be able to help you out.
I'd go ahead and add it in. It's cheap, and it's been proven to work for a good portion of the population. Worst that happens is you don't respond and you're out twenty bucks.I have been thinking of starting creatine, but I've been making plenty of gains without it.
Keep up the good work.