Yes, you can throw a plant into flowering at just about any stage. Just put a timer on the lights on a 12/12 schedule.
Optimum temp for photosynthesis is 72 to 80 degrees, so you should try to lower the temp a little if you can, it may help faster growth. One thing you can try is moving the fan to the top of the box (heat rises), that should make the fan more effective. Or is that the intake? Which way is that fan pointing, in or out?
The exhaust (outbound air) should be located at the top of your box, the intake (air coming in) should be located at the bottom of your box. If this does't lower the temp enough you can just try adding a second fan, 1 for intake & 1 for exhaust.
You may also want to make those lights adjustable. It looks like you plant may be a bit stretched because it was reaching for the overhead light. Those CFLs should be as close to the plant as you can get them without touching it. And a 3rd light would help too. There are plenty of ideas on making adjustable lights in the CFL & DIY threads.
Your lights also look like they're 2 different spectrums. If you're only using 2 lights you'll want to stick with 6,000 to 6,500k (daylight) for veg and 2,700 to 3,000k (soft white) for flower. If you add another light or two (something I would suggest) you can mix them. 2 or 3 daylight and 1 soft white for veg & 2 or 3 soft white & 1 daylight for flower. If you mix them with only 2 total bulbs then the plant isn't getting enough of the spectrum it wants most for the stage that it's in.
Another thing to help get it bushier is FIMing. Just do a search on FIM and some how to threads should come up. It makes the plant grow branches like crazy, you actually get branches coming off of branches, craziest thing I ever saw. Another way to go is topping it to get 4 main colas, Uncle Ben has a great how to thread for that.
The leaf damage looks like it may be nute burn, you may want to lower the fertilizer a little bit, or use a soil with less nutes the next time around. The damage doesn't look too bad though so it's probably not a major concern.
That's everything I could think of, hope it helps.