Obviously, to a great degree your suggestion is extremely logical and sound. I agree with all of it, in fact. The reason for my apprehension on taking this was that my doctor was suggesting it, seemingly not knowing a thing about any of the supplementation (or ingredients) I was already consuming and how they would interact, suggesting that I either find out from the pharmacist or just stop taking all of my supplements. When I asked exactly what it did, and he said "suppresses hunger", then explained that I don't really have a hard time not eating or stopping, he just continued to insist I take it without further explanation.
After the pharmacist also couldn't help me beyond "caffeine MAY be bad with it" and also suggesting that I just stop taking all of the supplements (accept the vitamins and fish oil - although she'd never heard of Flameout and suggested I get a "regular fish oil that was more trusted, like the ones they sold in their pharmacy"), I decided that I would do some research on my own.
I went to a ton of websites, searching for interactions with the ingredients and products I was already taking, but none mentioned anything helpful. Because of this, I'd already almost made my mind up not to take it. I only asked here because this is a community with some bigger guys in it who might have been prescribed this by their doctors who knew from actual experience how it may have interacted with the supplements they took. If I had zero interest in taking my doctor's advice at all, I wouldn't have even bothered asking anyone here.
Again, though, I do think that what you've said is sound advice for most people: trust your doctor over a stranger on the internet. I get that 100%, and I'm sane enough to do so to a point. My doctor appears to know dick about lifting weights or some forms of exercise (suggesting that I try and walk about 30 min a day, right after I told him I do a mix of fasted steady-state cardio in the mornings, some interval training, and conditioning martial arts). Realistically, I should actually just get a new doctor. Unfortunately, he's willing to bill my insurance for just about any blood test I want run, and I kind of enjoy not having to pay for regular t, free t, and e tests (among many others).