Do you have end stands to support the rockers on the end?

An engine will run just fine with the adjuster ran down, but it can take away from the amount of lift you get to the valve.  The pushrod ends up doing a sweeping motion instead of translating motion to valve lift.  I generally like to run a thread or so down, or as high as I can go without getting the pushrod into the rocker body.

I've had a lot of issues with porosity on BBM stuff.  You'll find it with a pressure test, but I doubt that it's a head/intake gasket issue.  I use Cometics all the time, never a leak. 

For hydraulic roller, I use Morel.   For solid roller, I either use BAM or Morel. 

A hydraulic roller lifter will always live longer (much, much, much longer) because they don't see the spring loads that a solid roller lifter sees and they don't have lash.   The combination of lash and spring load is what makes a solid roller lifter fail. 

A hydraulic roller lifter will pretty much live indefinitely.....think of how many 5.0 Mustangs and Explorers that have 100-200k miles on them. 

Too much lift and not enough spring load for a solid roller with that spring. 

That spring would work with a limited travel hydraulic roller, but probably not much else with an FE due to valve weight. 

Yes and a steel distributor gear.  I'd also recommend a steel thrust plate.

No need to get fancy with any of it.  Most bolts will clear the timing sets I use (mainly Cloyes).  Before Doug at POP started offering bolts, I would just buy a high quantity of 7/16-14 x 3/4 bolts from McMaster/Fastenal or use the ones that come in the Durabond engine finishing kits, then cut them down to 5/8".  Never had a problem.  Doug's bolts are made by ARP for T&D and they're already the right length, so I just have Doug send me a hand-full every now and again.

Not a fan of reusing the factory ones.  By the time I get them, they've been removed/installed 17 times and look like someone with a small screwdriver and channel locks tried to get them out.  I use mainly steel thrust plates, cam gears, and cams, so the new fastener "looks" correct. 

An unplated 7/16-14 Grade 5 fastener torques at 50-55 according to the charts and I'd rather not rely on threadlocker to hold it all in there, I'd rather stretch that bolt accordingly.  I personally just don't like the feel of trying to torque something with a Phillips (or PosiDrv) head.

For cam retainer plate and oil pump, I use Loctite.

On all other fasteners going into aluminum, I’ll use motor oil, assembly grease, anything to keep it from galling.