Whoa so many questions there Shaggnix!
Most people in here are really awesome SMN players and have high standards, you'd probably be overwhelmed by that amount of "stuff to do" so I'll try to list only the vital stuff, consider it a decent starting point. Just my take on it of course, I'm no SMN sage.
Which sets I need?
Idle Set - Normally people have at least 2 (avatar out, no avatar) but you could merge them into one for starters, I suppose. You can build your own and look for suggestions on page one. You're gonna need Refresh stuff and Avatar Perpetuation stuff. For this latter one don't go above -15
BP Recast set - One of the BP sets you'll need. BPs normally cap at 60 seconds cooldown, independently split in two for BPWard (Buffs/debuffs) and BPrage (attack). Thanks to gear with "BP Recast -X" gear you can lower that to 45 seconds (which means don't equip more than -15 in gear). With recently added "BP-recastII" you can furtherly reduce that timer to like ~35 seconds total recast. Special JAs like Apogee are a different story of course. Check the pieces you want and build your own set. BP-II is only present in two Reforged Relic pieces, on Incursion augmented SMN cape and on Seraphicaller, iir
BP Damage: Physical - A composition of gear focused on pet attack, pet accuracy, BP damage and where you can't find anything better, SMN skill (it converts to pet acc/macc). As for the staff to use here I suggest a Path A Tumafyrig
BP Damage: Magical - A composition of gear focused on pet stats used for magic damage BPs. You'll want to focus on pet magic accuracy, pet magic attack and bp damage. Again, SMN skill where you can't find anything better. I suggest Frazil Staff (drop from Shiva) for this. Alternatively there's Balsam Staff (from AH) and Eminent Pole (bought with Sparks of Eminence). Of course you could also get a second Tumafyrig Path B, or a Keraunos (Alluvion Skirmish) with the right augments if you're feeling lucky
Other BPs - Other BPs can be either debuffs (requiring pet macc/smn skill) or buffs (requiring smn skill to increase their duration, and/or "Blood Boon" stats to reduce the mp cost). But we're going into details there. For starters you could start with a single set composed of all the pet macc/smnskill you can find. You could also focus on SMN skill mainly and merge this set with the following.
SMN Skill set - This is used for Perfect Defense (more skill = PD lasts more) and for Elemental Siphon (MP recover JA, more skill = more MP). Can merge with the above. If you don't want to test your luck augmenting Kirin Pole for SMN skill +12, you can use a Tumafyrig (any path) to begin with, it has SMN skill+7
This is basically the core of what you need.
Start from your idle set, precast BP usage with the BP recast set, then midcast to the right BP set according to the BP you're using.
Some random suggestions on gear now. Unless specified I mean 119 pieces of course.
Reforged AF
Head is quite an awesome idle piece with its refresh+2 and I think atm it's the best for smn skill+. Given how Avatar's Favor changed lately though, you'll probably want to idle with an AF3+2 head.
Body is atm the best BP damage option, 2% more damage than the previous one (AF3+2)
I would ignore
hands and
legs, but consider
Feet please. They're one of the best option for BP damage (augmented Hagondes could be better for magical BP, situationally, but with this you'll have a nice option for both in a single piece)
Reforged Relic
Head is a nice option for magical BPs if you're not feeling lucky with Hagondes. (also nice to reach the -15 BP cap)
Body is a decent piece to idle with when your avatar is out, but a perfectly augmented Hagondes is going to be better (are you feeling lucky though?). You're going to want this body regardless though, because of the BP-II
Hands are an inferior but decent idle alternative to
Regimen Mitts with the additional utility of -BP and +smn skill.
Legs are quite a nice option for BP debuffs (and -BP!)
Feet are an wesome idle option (avatar out) and one of the two BP-II options.
If you have to set priorities here, I'd start with Body and feet, then the rest.
Hagondes set
All of the hagondes items can be augmented with Pet Macc, Pet Mab and Avatar Perpetuation-.
It can be pretty difficult to get the right augment on Hagondes set because of the very wide list of possible augments.
A dedicated SMN would want the pet macc, but I think you can skip it for now.
Which leaves you with the other 2 options.
Slots where you want to aim for Pet Mab are Head (only other decent option being Reforged Relic), Hands (only other decent option being Nares Hands or the Spurrina Gages, good luck with them) Legs (other option being Ngen Seraweels, drops from Legion, and AF3+2 legs but only for Merit BPs) and feet (situationally better than reforged relic, if you get good augments)
On Body you'll want Avatar Perpetuation -, makes Hago+1 the best Idle body for SMN. If you don't feel that dedicated just settle with reforged relic.
Empyrean Armor
No reforged version out yet, let's see the current options. Talking about +2 of course.
Head ==> Nice idle piece if you're using Avatar's Favour
Body ==> second best option for BP damage after reforged AF
Hands ==> meh
Legs ==> decent damage option for merit BPs
Feet ==> they were a nice avatar out idle option, but now you have reforged Relic.
Neck ==> still useful, get it
Other notable pieces
SMN skill grip (buy on AH)
Evoker's Ring (quested, get it it's nice)
Andoaa's Earring (drops from Calimh)
SMN skill belt (AH, expensive though)
back => one nice option comes from Incursion, the other from 2nd NM in Yorcia Delve. Augmented Conveyance cape is also pretty hawt sauce.
Marduk+1 => There are some nice smnskill+ option, and you can build some decent precast sets. If you already have them or are regularly doing Salvage go for it. I wouldn't bother otherwise
Globidonta Ring ==> from Incursion
I think that's it, I likely covered most of the basic stuff.
Quote:
Merits? are the group 2 merits any good? Just unlock or should i max a particular 1? Group 1?
It's all a matter of personal choices.
For group one I went Pet Macc/Mabb 5/5.
For group two you'll hear all sort of suggestions. Who would say to go 4/5 in one and then 1/5 in the others, who says to get 5/5 in two, blahblah.
Kinda depends what sort of content you do and hence which avatars you use most. It's hard to give you a definitive answer here.
I went 3/5 Garuda, 3/5 Ramuh and 1/5 in the rest. I kinda swap them somewhat often though.