Ok so I have a BB curve right now.

So when i get emails it pushes to my BB most of the time with no problems... However if i log onto a computer and delete the email, it will not delete from my phone...

will upgrading to hotmail plus solve this? Will my hotmails still get pushed to my BB as fast as before?

Nope, it's just very sporadic.

By the time it reaches your inbox it is already on its way to your berry. This is why it does not delete from your berry.