Absolutely right. Anything 1/2-28 and bored for .223/5.56 will work. Again, assuming it's one of the newer Tactical models (post-2010, IIRC). Some of the early ones were threaded either 5/8-24 or 7/16-28 (again, IIRC).
It seems the factory sights are a friction-fit with a roll pin to make the lawyers happy.
You can punch out that pin and work the front sight loose, then install any front sight you'd like.
That being said, I haven't found many front-sight-only replacements that wouldn't require some amount of work -- be it drilling and tapping, cutting a new/different roll pin slot, or clamping onto the barrel.
As for the pin-on FH/MB, you're right. The Choate, Masen, and (ch)NcStar brakes/flash hiders aren't compatible with the threaded muzzle on the Tactical models. AFAIK
, the only way to get one of those to fit a threaded muzzle is to lop off the threads and essentially make it a "short" standard barrel.
KMO/Kelly/Mo-Rod is now making the Mo-Reaper, which is an integrated front sight (uses SKS/AK front sight inserts) and muzzle brake. He has one for the Tactical models that deals with the thread+roll pin vs. roll-pin-only differences. Many members are singing the praises of this product, but I've never held one in my hands to give you any opinion about it. I can say Kelly is an active member of the forum and is a real knowledgeable feller.