Elise needs something to get back into the meta/be a little more viable, but I don't think this is it. Elise doesn't really teamfight in human form besides using her E for a stun. Making her Q a skillshot would probably just hurt her more, even if there was a damage and range trade for it. I think she should have some sort of Ult CD reduction, whether conditionally or just more when she levels her R, the reason she feels clunky to me is that she can't transform quickly enough to make the most of both forms. Of course you can buy CDR in items but Elise's choices for that stat are fairly limited as she has to get damage early and get tanky later. Her best bet is Frozen Heart, but she will usually end up low on Health as a result. I feel like a change in items could benefit her greatly if she has access to a good CDR option. One could maybe build Magus if Elise liked it a little more, but as it stands, she is better off buying Cinderhulk and opting for Haunting Guise and Abyssal as her early damage sources.
Other than an item shift, I feel like she needs to be able to get back in spider form quicker after transforming into human form for a stun, Q, W combo, which takes all but 2-3 seconds. This would allow her to make the most out of her spiderlings and Q execute. It would also help her be a little slipperier with her Spider form E letting her escape some sticky situations if she transformed into human form at the wrong time and needed to switch out again. (this could be bad for players punishing her so there may be a balance issue with this, though I don't think she would be as forgiving as Lee Sin with his escape ability). I think the reset should be if she lands her Human E which is a linear skillshot with no damage, so giving it that extra utility will make it more pivotal to her success, even if it already is.
I don't think her Q or W should be touched other than slight number changes if she is too strong or too weak. She is very unique in that she has a %max hp and a %missing hp ability, and I would like that to be preserved (even though this has caused a lot of balance problems in the champion). Her Human W maybe could get a slow added to it (a small one), but right now it serves it's purpose to help Elise farm AND check for enemies which is a great utility.
That's my piece. Later. Good luck out there.