I’m getting back into the game after a long break as well. Quite a lot has changed, so I’m still catching up. Just theory-crafting but you need to decide how glass-cannon/specialised you want to go, and that will determine how far from “fit” weight you are, either towards obese or more likely now due to stats rebalance, towards skeletal. That then determines your race choice. Race is the only thing you can’t change later.
If you want to be able to melee effectively, then stay within lean/fit/stout range at 30 years old. This maximises your points, and you need as many as you can get. I’d recommend either pure Tindremic or Sarduccan. You are mobile but running away isn’t your only option.
Human is still probably the right choice if you are dedicated to elementalism and go skinny or even lighter. In that case you could try mixing Sarduccan/Sidoian at 62 years old. Just remember Sidoians lose quite a few attribute points so you will be less flexible if you change your mind later. Khurite and Kallard will tank your int so are non-starters for a mage. You won’t be outrunning determined footies due to low stam with this build, so you’re going to need a backup plan for those times you aren’t with guildmates, and that probably means taming/domination, and all the pain of that. Sidoian mixes can also be converted to obese mounted mage if you want to use it for farming or just want to change the build completely later.
If you decide to go full meme skeletal , realise it’s not just HP you lose. Look at the low stam and carry weight. Those are going to be painful, just as painful as obese on foot can be. Depending on what the elementalism curves turn out to be, I’d say it’s unlikely to be worth it.
Cleric, Soldier, Versatile, Eruidite, Northerner, Southerner and Tactician are the must-haves in the gift tree.