Sorry, someone will have to fill in the finer points, but for a few of these:
1: If you have a tank friend see if you can get them to meatshield for you for a few tier 8 delves, just to get you off the ground. Though I still struggle solo delving on DPS classes even up at 607 ilvl, personally.
3: At level 15, I believe. Blizzard didn’t like people leveling Brann on ‘easier’ content, so only bountiful delves offer experience past that.
4: No daily cap, but see above.
5: Four are available per day, and reset when daily quests reset every day.
7: Did this duo and we had to go double dps. Pretty tight DPS check getting the egg killed before the spider spawns, or if it does spawn, you’ll need a second kick for the spider and one for Zek’vir. It’s doable solo but you gotta crank the damage.