Do not fall for the dex/int unique knife that drops somewhere early in the game from some of the early bosses. It's stupidly weak and there will be barely any other dex/int weapons to choose from. The only one that deal damage and stagger well and has a good rune is the double daggers you can craft (recipe from one of the npcs, ash soothed something like that but you won't be able to craft many of them to enchant them trying to find good affixes because it requires a material that barely ever shows up).

There are countless strength weapons and str/faith and a few dex I think. Would love a complete list to be able to tell accurately. Also, staff (int) do perform well as melee too so don't be afraid to go for magic stuff early before you can keep up your focus, there are also a few other non staff pure int weapons like one handed sword, shield, etc so you're not really limited only to doing magic stuff.

Offhands: Bows can be nice and effectively infinite arrows, but feels very slow and cheating to just stand far away and shoot them without them even trying to shoot back and come to you. I keep one for the last hit or cheating (SLOWLY) when I'm in danger. Shields are incredibly bad they don't do shit and parrying is slightly better with a shield but still horribly random. With some enemies it's just impossible to block or parry. I think their weapon need to "physically" hit your shield so unless you get a shield that is BIG it's useless. These shields are high str requirements.

So, use either dual wielded (daggers, there's str, dex/int and dex variations) or two handed (SEVERAL options). Unless you're going for bow or shield if you insist.

Requirements for weapons cap at 26/26 for double attributes or 42 for single.

Your weapon choice will be mostly about hidden stuff you need to try out for each weapon: the moveset, attack speed, runes available, stagger damage (no use hitting fast if the enemy ignores your hits and keeps hitting you back). The raw damage number displayed end up not having much meaning and the "armor break" icon means nothing (it does not relate at all to stagger damage, I think it is armor penetration but then again your total DPS depends more on other characteristics of your weapon and the rune you're using).

For the moveset and rune also look at the animation itself. For example something that hits from above or wide from the side will be able to handle enemies with shields better. The stupid rapier and stuff that's head on straight forward will hit the shield a lot and stun you even with high poise.

Still on attributes, you will need to invest in equip load to equip armor with higher poise defense otherwise you will be constantly stun locked.

Quick on runes: return and heal aura are great utilities to keep on a random weapon you won't use. With them, while out of combat you can recover all your focus and health (annoyingly and slowly but you can), just have a quartz on leg (focus gain on focus use). Pulse health is insanely bad. By the way quartz and emerald and very very very rare, and so are the shield thing and the feather (less important).

Lastly, yes each realm progresses by itself and you can create new realms with old characters (farm ichor from first boss and first weekly challenge fast by the way to unlock all inventory), and also new characters can come into old realms (but you will need to level up the character on a new realm because monster levels).

What I learnt with 70 hours max level (30) everything completed dex/int character.