Welcome to the OP. You have a lot of good questions. My opinion based on my experience FWIW. I don't hunt in briars but do hunt areas with lots of stickers (similar issue). Personally, I use and prefer chaps. Depending on the country and conditions you hunt in, you can get waterproof and/or snake proof if needed. I use the regular chaps and they work well. If the boots you bought don't fit right with the socks you intend to wear, I'd take them back for a refund or exchange. Boots are too important to hiking to wear something that's too snug. I rarely wear a jacket cause I'm usually hunting in warmer weather. If I had to, I like being able to unzip a jacket as opposed to a hoodie without that option. I also rarely wear gloves unless run and gunning for turkeys so couldn't offer much opinion there. Your 20 gauge should be fine for the game you're hunting. Using a regular bead or fiber optic front sight seems to be a matter of personal preference. I've hunted with both and each works well. Hopefully some more people chime in here. Best of luck this season.