Another thing I noticed after I removed the rocks and placed him into the clean tank with salt is that he doesn't so much hang out at the bottom, he looks like a dog sniffing for something (specifically, when my parents dog finds a bug, he does this almost like he's about to snort it up he gets so excited), kind of runs his nose along the bottom swimming around. Sometimes he falls asleep for a bit while he's down there. Not sure if either of you knows what this means or if it's significant at all, but I thought I'd at least mention it.
Nope, just scrounging around for any food that may have fallen. They are very curious and don't shy away from much :) He is just tired from all the excitement of treatment so he is like a little kid.. play play.. Zzzzz... oh wait, I was doing something.. play play Zzzz... huh? Oh.. play.. Zzzz. It's perfectly normal :) As long as he can't get stuck between/under and of the rocks, then it's safe and normal.
I forgot about the flaring.. I don't remember it as mine flare a lot during the day because of females between males, and I never see them poo.
Clamped Fins, no appetite, darting/rubbing, loss of color, lethargic are the symptoms you will be looking for when it comes to velvet. A lot of the times you will see other colors on them when you shine a bright light, or use a flash on a camera. None of my fish look the same when I do that versus how they look under regular lights. If he isn't showing any of the other symptoms, then I wouldn't worry too much about velvet.
The flaring doesn't always work, but it's worth a shot. I have a boy who would only go if I did a WC with warmer water. The little bug.
Frozen brine shrimp or daphnia can help them go, think of it as the betta friendly laxative that they will love.
Myates- Hmm... he does dart around a lot... and that seems to be only somewhat recent...
Silverfang- A WC? I'm not sure what that means... unless you mean a bathroom... and then I'm really confused. I've read about daphnia... if he hasn't gone by this weekend when I go to Petco, I'll see if they either have any daphnia or frozen brine shrimp, or can suggest a place I could go to to find some.
by WC I mean water change. You're more likely to find frozen brine shrimp. They come in sheets or cubes, if you can, I find sheets easier to break a small bit off. Of course when I feed I'm feeding a dozen hungry mouths.
If you can, get a picture of him with the flash on, and one with the flashlight shining on him and upload it. I'll look for it tomorrow. If he has it, it will be easily recognizable and we can begin treatment on him.