I have a 700 and bought a cover off of Amazon. There's ton of them in a lot of different sizes. I think there was a ten or fifteen percent discount available at the time. IIRC, it was about $40.00 delivered. It has a zipper and is quite nice.
Honestly, the Recteq cover did nothing for me and...
I wouldn't consider LocTite as an "Anti-Seize" compound. But, being a liquid, it will help lubricate threads on installation, if only to a minor degree though.
And, now that I think about it, I'd shy away from using LocTite on stainless to stainless unions on the grille. Particularly on the...
IIRC, both the horns and screws are stainless. Provided that is true, stainless on stainless is very prone to galling. If the union galls, it will be difficult, if not impossible to get the two pieces apart without destroying one or both pieces. I'm pretty confident that's why RecTeq recommended...
You will want to be able to take it apart for maintenance. It WILL get all creosote'd up and you WILL need to clean it. Just keep that in mind, no matter where you mount it.
And.........that thing is HUGE ! With a full fuel load, it'll probably provide 8 hours of smoke. I have a Smoke Daddy...
I think Boar's Head is probably a good start. May not be the best, you may have to find a specialty German/Austrian/European Butcher Shop/Deli that makes their own for "the best".
I am not of the belief that Lavalock has anything to do with Lid Pops.
When I start my 700, the lid is always open, until the fan kicks into high gear and the smoke decreases (225 degree setpoint). Easy peasy, no issues ever.
Here's a quick video of what's known as "lid pop". This one is pretty mild. Some can be quite destructive. Essentially, when the grill is first starting, the smoke is so thick that it risks being explosive. Sometimes (not always), an explosion will occur. I always start my 700 with the lid open...