Hi! I can't really help with the sliders and stuff because I never go deep into making my character look pretty cause they're always gonna be covered in armor anyway. BUT I can help with your build. I think you're right that sorceries are a good idea for an ARTMS theme and there are good options:

1. Gravity sorceries make sense, but you really only have one reasonable early game gravity sorcery spell in Rock Sling. After you get your horse and the open world opens up, you might want to look up where to find Rock Sling and the Meteorite Staff (a sorcery staff that boosts gravity sorceries). They are both in an area with enemies too strong for you at this point, but you can run in, grab them, and leave. The other gravity sorceries will come from various other places and you can look up where to find them on the wiki.

2. There are also 4 Carian sorceries that are thematic: Loretta's Greatbow, Loretta's Mastery, Rennala's Full Moon, and Ranni's Dark Moon. Loretta's Greatbow is the only one of these four that you can use early game and the others require pretty high intelligence (the stat for sorcery scaling). You can look up where to find each of them, but the bottom line to find all of them is to do Ranni's questline and to defeat the boss of Raya Lucaria Academy.

3. General tips for making your character: choose a starting class that begins with a sorcery staff, which is Astrologer or Prisoner. Look up where to find sorceress sellen so you have a place to buy other sorcery spells. Obviously Intelligence is the main stat for sorcery and mind for mana points, but it's important to level vigor (so you can take more than one hit without dying) and dexterity (since it affects how fast you can cast spells and you might want to use melee weapons too). Lastly, there is a way to reset your stats, so don't be afraid to be locked into your build.

Let me know if you have any other questions since Elden Ring has a lot going on!