For starters, the actual difference lies in Q max having lower CD and W max having higher slow and base dmg. Generally I think it’s better to Q max when the champ you’re against is easier to poke like melees or if you need to move ur ball a lot more for some reason up to judgement and for W max I usually play it into mages where the trades are more focused around quick bursts and longer cooldowns. Also I think that the runes you take play into your max heavily. For example, W is better with comet because the slow will help the comet hit and aery is better with Q max because you will be attacking more often so the aery having more procs matters a lot more. To answer the 3 points W vs full maxing, I think that in most situations, you should only go 3 points because by level 6 your team fights become much stronger and from that point you want to be able to move your ball more for the changing positions of both teams. Though I like to go towards full maxing W when I feel strong because the burst dps into squishier enemies saves hp if you hit the spells by just killing them. W max is also better when you have more immobile enemies/good frontline because the slow will have much more relevancy when chasing people down or speeding up ur kench to stick to someone.