Ok so if you’re only a pvp player in WoW - then your options for gear are:
All ilvls referenced assume PvP instanced content.
So basically if you farm up some honor for a full basic pvp set, you’ll have 411ilvl, and your progression goes up to 424 if you choose to do rated arenas.
Does all that sound right?
yes
10char
Fairly certain conquest doesn’t upgrade to 424, it just is 424. The base ilvl is what can be upgraded but the PvP instanced ilvl is 424 from the jump.
You could craft 1 piece now and 1 next week that will probably be mando due to their effects that would be 424 in instanced content.
Oh! I assume that’s the same as honor gear?
So if you don’t plan on using your honor gear in PvE, there’s no need to upgrade them since they’ll always max out in PvP?
Correct. You just need the base set. Upgrading it just helps its pve item level.
Correct
They left the upgrades in for PvE purposes to give people something to spend honor on and even though I don’t like it, still has a gear progression aspect outside of instanced PvP.
I don’t like it because I like going back to do old stuff so I prefer the gear to just have a decently high base ilvl and a pvp ilvl. Literally WoD gearing, but this is better than SL so I’ll take it.
I think this gearing is more fair than SL and WOD.
You can climb up to have parity with PVE or just enjoy PVP. We’ll have to see how it plays out but overall seems like Blizz listened and is trying to do right by us all.
Honestly I am loving the new system too. Eventually I might even get serious about some alts for BGs/Solo Shuffle this time 
To add:
There is another option for “starter” pvp gear, the crimson combatant crafter gear. It scales to 398 in pvp combat. This can be crafted and bought off of the ah for pretty cheap.
There is also crafted pvp gear that scales to 398 in pvp as well. There will be other crafted pieces that scale to 424 as well I think but they are either MEGA expensive atm or just hard to find period. I went looking, one pattern was selling for millions.
398 crafted gear
408 war mode gear (upgraded to 421 with trophy)
411 honor gear
424 conquest gear
waiting for ruffle to come in and start flipping out
Same. Just hit 70 on Evoker 2 hours ago and am fully PvP geared already and blasting kids with 100k disintegrates.
If I’m fully honor geared, is there any reason to continue grinding honor?
Will conquest pieces require honor to upgrade?
Supposedly yes. We’ll have to see this Tue though.
The honor to upgrade conquest only affects PvE ilvl. It will scale to max I lvl of 424 in PvP. For example let’s say the conquest pieces are 380 ilvl in PvE but 424 in PvP you can upgrade it to 390 PvE but it will stay 424 in PvP
No.
Also no.
421 with trophy?
Yes. 
Trophy quests aren’t available yet iirc but will become available Tuesday.
I think there’s a weekly that gives you enough for 1 piece.