Bought an XL w/ all the trimmings, have many questions (some might even be previously unanswered!)

So.  As implied, I bought my first egg, as having a trailer smoker in the driveway just isn't plausible anymore. 

It's an XL.  Also added a plate setter to the package.  I did a lot of reading on this forum prior to purchasing, and saw some people complain it's hard to maintain a low & slow temp on them.  So I bought a CyberQ Wifi - which I'm pretty sure I had to do anyways, since nerds are obligated to nerd up everything.

So.  Questions.

-Since I'll be using a stoker tool, that obviously solves the issue of how wide to leave the bottom vent open.  But what should I be doing with the daisy wheel part up top if I'm seeking a temp in the 220-240 range?  Leave it full open and let the CyberQ work it out, or leave it almost completely shut as though I didn't have the technology?

-Are there any 3rd party cover options for the egg + the long table?  I don't so much mind paying the Germany tax for things for my car, but the Green tax for the egg bothers me.  $130 for a cover?? As I live in the Seattle area, it's not an optional thing.  I just don't wanna pay that much for one.

-What kind of grid extension options do I have (again, likely 3rd party)?  I'm in a situation where I've gotta do 2 briskets and 2 butts for a Q in the not so distant future, but the "official" XL dual grate item from BGE doesn't seem to put enough distance between the 2 levels to where I could pull that off with it.  I'm also not terribly amenable to buying a 2nd smoker right now for obvious reasons.

-For Seattle Eggheads:  Recommendations of where to go to buy accessories?  The place I bought my egg from was one disaster after another (more on that in a moment).  I'd rather not give them any more money.

-Reporting bad dealers:  Does BGE care if their dealers suck or not?  Is there a reporting mechanism to rat out bad ones to them?  Does this board have a place to put up reviews of them?  The one I chose did all of the below and more:

1)  Promised 1 day delivery; took a week
2)  Had a deal that included assembly; their delivery people left everything in boxes on my deck
3)  Tried to get me to pay another $75 for assembly, even though it was supposed to be included
4)  Assembled everything after I threatened to return it all; had given me the wrong table (I ordered tile top, they sent wood top). 
5)  Had to have them come back out to replace the table mishap.  Turned out in the 2 times they had come out and assembled everything and nested the egg into the table, failed to inform me that BGE sells spacers to separate the egg from the wood; that leaving it on the wood would likely set the table, my deck, and potentially my house on fire, or that firing it up like that instantly voided the warranty.  Thankfully, I looked at it before using it for the first time and thought "I'm no expert, but it appears that my grill is sitting on KINDLING", and didn't do any of these things.  Therefore, they tried to burn down my damn house.

-Per (5) above, I went to Lowe's and got a garden spacer, 2" thick and 16" square.  I don't know how much the "official" solution costs, but I'm sure it's more than the $1.59 I paid for the stone.  Was the best I could think of for a Sunday.  Sufficient heat diffuser for the egg and table, or do I need something more?

-Seattle Eggheads, part deux:  So apparently $679 only buys a table made of unsealed cypress (Whiskey.  Tango.  Foxtrot?).  During that same trip to Lowe's, bought some Olympic seal/stain (rosewood, for those keeping score in the home game).  Sufficient for the wetness out here, or do I need something more to maintain the appearance?

-Seattle Eggheads, part trois:  Anything special I need to know about smoking in the Northwest?  These 98 degree and sunny days like this weekend are obviously pretty rare.  Is the 1.5hr/lb cooking time for low/slow applicable up here, or does the more moderate temperature throw that off?  I've got a couple of briskets I'm going to practice on between now and the "big" BBQ where failure isn't an option, just hoping to know what to expect.

Thanks for reading my novella!