Firemaking, combat, and runecrafting, as your other skills are kinda useless. Try to do stuff that you can still store into your bank so it doesn't get destroyed.
Personally, I would prefer to be a member earlier, as there are TONS of benefits you overlook once you are higher level. If you want only a short time of members, then definetly raise magic to around 40-50, as its REALLY useful. Also raise runecrafting. Aside from that, you have REALLY good skills for starting members. Make sure you do all the quests you can for f2p
Personally, I would (if you don't mind clicking) use crumble undead. The other easy way if you don't want HP xp, is to use telly to camelot. If you can't use that, then use firebolt. Of course I recomend making your own runes, for the xp. The best way is just stick to it, and don't stop for any reason. Whilst playing RS, just keep going.