3U is actually very easy to improve in. All you have to do is put in the work. But if you can't find motivation for the life of you, just drop it, I guess. I think you should persist, given how well it scales.
You can't solve that algebraically, I'm pretty sure it's a transcendental equation (someone with uni maths experience may want to correct me on this).
Use newton's method/graphing/interval method if not blatant, thoughtless trial and error.
2u maths will definitely be a LOT more achievable if you find someone to sit down and identify your weakness, and tell you exactly what to study and concentrate on. Either get a tutor, or consult your class teacher =]
Memorise your essay until you can type it out blind with no assistance. That's what I did for English.
For everything else, watch some cricket and chillax =]
Impossible to tell, since you're coming first in everything. You need someone experienced to actually look at your marked scripts and judge whether they're being marked fairly (very unlikely given you go to a 500s school).
Keep it up, nice work btw =]. If the 95 in bio is anything to judge by...