http://capa.wikidot.com/guide:phantasy-star-online-2-summoner one of the best guides for summoner

so redran is good for "endless" missions, jinga is best all-rounder (short KO timer, low cost PAs and gains good pp on hit, also somewhat tanky), melon is best boss killer (once 14* comes out as he take almost no dmg from melee bosses), synchro is best boss killer when you want to kill it as fast as possible and the boss generally doesnt move around a lot or is slow. viola is fun but shes not that great, maron was good but the dmg cap makes it worthless. Also redran can be good for bosses if they have a lot of breakables as he can target multiple targets on a boss at the same time.

I use redran in ultimate quests when im farming and everything else melon or jinga

Depends if you want to play defensively or not, if your worried about dying then get hp, but me personally i went full damage since its very very unlikely ill die. For a cheap affix set get noble casting elder soul casting 4(i used several casting 3 and a +40% chance when i affixed), gives you 95 tech and 6 pp. saiki set is BiS currently as well for when phantom drops. i would just add stamina 3 or 4 to the affix i said previously for a 4 slot if you care less about cost.

If im being honest i dont think health is that important, if you can get it without sacrificing tech and pp then get it but other its not really necessary. Mostly because of Dear master (dia master) makes it near impossible for you to die as long as you dodge the big hits.

@MoodyCascade259 well its based off JP since they play on JP, what conflicting info are you talking about? i can clarify

saiki set atm, slave barl or nemesis for weapon and do your client orders from pietro for candy for candy box, also get his card and get 10 gifts from him to get the support roll and make another character to repeat that (getting 10 gifts from pietro for suppor roll) when your bored

Slave barl potential is really good as it gives a knockback shield and increased active pp regen and on hit pp regen (according to jp wiki) other than potentials we cant do anything with them.

http://capa.wikidot.com/guide:phantasy-star-online-2-summoner

one of the most indepth guides for summoner

Just put 5 points in dear master (dia master), dodge the big hits and dont use alter ego at wrong times and you literally cannot die.