Re: Tips & Thoughts for enhancing my Windham.
There are gear snobs out there that will trash anything that's not on their top tier list. In many ways they are correct in their beliefs and I agree with them. But there are fanatics who carry it all to extremes and you may be subjected to a lot of brand-bashing (in lieu of actually answering your questions) before this is over.
I also believe that it is best to buy the best you can afford, but I also enjoy my niche of making my cheapass POS guns perform as well as I can possibly make them perform by working on them myself. I own a Colt, but I also built several ARs from BLACKTHORNE KITS. (This is highly frowned upon) In taking this route, I have learned much more about the weapon system than I ever would have if I'd simply bought the high-dollar trouble-free weapons to start with. But in an effort to arm an entire family with ARs, I had to take the cheapest route available at the time. I applaud anyone wishing to improve their weapons and learn the system.
I will say also that in my experience, Most any AR will be accurate with ammo that it likes. The best way to provide your weapon with ammo it likes is to reload. Any AR with a properly torqued barrel and decent optics (also properly mounted and torqued) will most likely do MOA or better at 100 yds once you find the right ammo. If you don't reload, don't skimp on ammo if you are going for accuracy. Besides optics, ammo is the most important ingredient for an AR to shoot well. In all my dealings with the sorriest, cheapest ARs out there, I have not found one yet that is not reasonably accurate with good reloads tailored for that gun.
If you are going for accuracy, get rid of the stock trigger as well. I haven't spent the big bucks on a trigger yet, but I get by fairly well with my Armalite and RRA 2-stages.