Didn't Super Broly already HAVE limitless energy? I thought he did since he didn't seem to tire even slightly while in his LSSJ form. And I thought the point behind LSSJ was that they had limitless energy (so much, in fact, that it's practically a ticking time bomb when in use).
As far as a love triangle between Broly, Kale, and Cheelai, I'm not entirely sure that's a good idea (most times with few exceptions love triangles kind of reduce characters to their worst aspects). Besides, Kale doesn't even live in Universe 7, she lives in Universe 6, so unless Beerus for some reason wants to repopulate Universe 7 with Legendary Super Saiyans, I simply don't see the two literally seeing eye to eye at all. Heck, wasn't Kale in at least the anime implied to be a lesbian? I'm not entirely sure Kale would even have the hots for Broly (even if I DO think it would have been a LOT better there than having Kale just crush on Caulifla. At least the manga toned it down to infer her attachment to Caulifla is more because she owed her for taking her in and not necessarily romantic-based).
@Nerve of the Hybrid Cell I don't necessarily mind depowering tropes in and of themselves, but they definitely need to be plausibly done. And yeah, I know about Spiderman 2's depowering trope, and thought that was stupid. He got his powers from being bitten by a radioactive spider. That's not exactly something that he can just randomly lose like that (especially not mid-swing after being yelled at by Mary Jane.). Also agreed to some extent regarding love triangles, they generally just bring the worst out of people and make ALL parties look completely unsympathetic. I think the only real exception was The Little Mermaid, and that's only because in that one, Vanessa up and out brainwashed Eric and Ariel actually did consider just letting Eric marry Vanessa despite the heartbreak and being damned otherwise and only changed her tune when she realized Eric was brainwashed.