So starting my first run-through with an INT build caster and looking for tips. I'm SL30 and just hit Blighttown and currently using nothing that is upgraded (mostly chain, grass crest shield, drake sword, bellowing dragoncrest ring, ring of favor and protection). Nothing is too challenging so far but I seem to be relying on melee a bit much for a caster so I'm wondering when/if that changes? At what point will it be mostly spells instead of swords? What do I need to make that happen?
You need that crown!
You say you're relying too much on melee? How many attunement slots do you have? Are you aware you can buy multiple copies of spells to have more shots available?
Ditch the grass crest, it's useless on a sorcerer. I recommend the eagle shield from blighttown.
I highly recommend you purchase hidden body after you rescue Dusk, that spell is amazing.
I personally did a pure sorc run and didn't use melee much if at all, but I put all my points into vitality, attunement and intelligence. And of course buying spells, which is expensive as fuck. Early on you might wanna get those heavy soul arrows... they're very slow so be careful casting them. Later on you can ditch them for better stuff. Saving Logan should be a priority, after you do rush back to Firelink to do some purchasing.
Save EVERY soul item you have... they're very useful for purchasing spells since they don't go to waste when you die unlike the 200k souls you had on you.
All those points you're putting into strength and dexterity and endurance are screwing your sorcerer playthrough.
On my pure sorcerer playthrough I went full caster as soon as I hit firelink shrine. Remember you can buy spells from the blacksmith in New Londo.
As for weapons... something light that takes very little stats and stamina to use... like the rapier. Forget about catalysts, the best one is the one you started with until you hit the Archives and then you can find an upgrade.
From my experience the single most important thing for a sorc run is to kill the hydra as soon as possible and ignore all stats but attunement, intelligence and a little bit of vitality. Once you feel comfortable you can start upping a little bit endurance and some strength to hit the requirement of the Eagle Shield.
It was the easiest run I ever did. Sorcery is so, so imba. At the start you sort of have to use heavy soul arrows which are extremely slow, but afterwards.. oh boy.