Always look up ahead, electrocute and meteor are getting 2 overheats soon so i rather take ele3 (wich its super good anyways) to get the best of electrocute, wich is one of its best skill RN.
Unless RC gets a HUGE buff soon its not worth the circle, i tested ele2 rc w2, and ele3 wl rc, and none of them are better than just elementalist 3.
Build-wise this is what im currently using but you can always change stuff:
https://tos.neet.tv/skill-planner#2111bbbff.1b233f51657585.1f3f5a85.1a28314a51
Lethargy: You can take off points from lethargy and add them to energy bolt. (Wich has no cast now and does good damage)
Surespell: Lv5 its enough for 100% uptime but if you dont like to recast spells you can add more points.
Rain: You can take off 1 point from the skill you want to put it in rain, but TBH its very situational and most of the time you are not going to use it, even if you can.
Prominence: Its bad RN, low damage, long cooldown and still somehow random. Some people take it at 1 to have “something to cast while in CD” but with the 2 OH to electrocute and meteor you might dont even need it.
Freezing sphere: Deals good damage but if you are thinking about ET, better level up your main AOE skills. Same as prominence some people like to put 1 point here but as i said before, better get the best of your AOE’s for ET.
As for warlock, invocation 8 its enough for 100% uptime and evil sacrifice can be very useful to move your spirits, most people tend to overlook this skill but it can help a ■■■■ ton in boss battles specially in salus where there are a lot of mobs to kill and all of them become extra damage to the bosses<3.