I don't think I'd worry too much about the bristleworms. Most likely, you won't see any worms on the surface of the rock. They are pretty darn good at finding all the nooks and crannies and will be deep inside the rock. You'll see them after the rock has been in your tank for a couple weeks and they start poking their heads out to see if it's safe! I'm with Roka... I consider them part of my cleanup crew as they help keep my substrate stirred and eat all the nasty stuff the crabs and snails can't reach. There are a few varieties of worms that will cause problems with corals, but I don't think those varieties are actually very common. And if you don't have corals, or don't plan on having them, then it really doesn't matter at all - in my opinion, of course! If you really want to rid yourself of them once the rock goes in the water, there are traps made for them. But you're going to be amazed at how intelligent those buggers are.
I've read stuff both ways regarding placement of your rock - whether or not to elevate it. I went with the "put in firmly on the bottom of the tank" crowd. The main reason is that with the arrangement of rock I wanted, if it wasn't down hard on the glass bottom I would've always been worried about it being undermined by who knows what (Bristleworms?!) and falling hard against my glass. Not something I wanted to experience. So it's firmly on the bottom with about 4 inches of sand surrounding it. Short of an earthquake, it's not coming over.
Regarding your water turnover rate... one of the previous posts mentioned a 25-30x turnover. For a larger tank with corals, this might be a good flow rate. But I think for a small tank for fish only with live rock (FOWLR
), this might be a bit too aggressive. (I didn't see any mention of coral in your tank - but if so, disregard my blabbering.) I originally had just shy of 20x turnover on my 46 gallon when I started. After I put my first fish in (O. Clown), I had to rethink my plan. He was really getting hammered and I'd done such a good job in making a "chaotic/random" flow pattern the poor guy couldn't find a calm spot to call home. I'm now just a little over 10x turnover and he's a very happy little fish. I've introduced some zooanthids recently that like the lower flow and if I ever need more flow for certain corals I'll just use on of the little Mini-jet powerheads to provide for "spot" flow. I guess my point is if you go with high flow, don't be afraid to slow things down if your fish seem stressed or just plain mad at you!
I'd highly recommend going with the live rock. When I look at my tank which is only 4+ months old, I'm absolutely amazed at the amount of life that came in with it. I'm still finding new things on a weekly basis. And the fact that I'm taking care of my biological filtration needs with no fuss is pretty darn cool too!
With the bioload you have in that tank, I'd sure plan on getting the best protein skimmer you can get. While it won't help with your water movement, it will pull a lot of gunk out of the tank that will at least help reduce the waste in that tank. And as others have pointed out, I think specifically that tang is - or is going to be very soon - very crowded in a 29g tank. I'd love to have a tang, but even in my 46g I think it's too small of a tank. If you absolutely want the coral beauty, then you might look at finding that tang a new home. Just my opinion.