Max out Dex and Con, Don't be concerned Substantially about Str or even the +2 raging damage they will not use (3rd option for stat placement). Innate spellcasting is usually welcome to the Warlock due to their very limited number of spell slots. Speech of Beast and Leaf is useful, https://dicestone24680.bloggazza.com/27510166/facts-about-genasi-d-d-revealed