Hi Silicon,
I'm new here, but thought I'd add my 2cents.
I noticed you said that you tried every character except the Dark Elf. Any reason why? I only ask because my 2 favourites are the Dark Elf and the Wood Elf (though I haven't tried the Seraphim yet). I find the Dark Elf is very powerful, especially if you choose Dual Wielding as your first new skill.
For the Dragons, don't kite them and don't try to take on 2 at once. What I usually do is wait for a dragon to be turned away from me and then run in and under the dragon. It won't be able to use it's breath weapon against you that way. For the Frost dragons, I usually start by kiting one to get it to come after you 1 on 1. Once it runs after you, I run in under it. Once one is down, I repeat the process for the second one.
I also do every side quest I can find to get my XP/level higher. You said you were level 46 after finishing silver. I usually try to be between 40 and 50 by the time I finish bronze and then in the 70s by the end of Silver. But that's just me. As it was said above, the next tier scales by your level, so ending at a higher level doesn't really benefit you unless you're going into Underworld where things are much tougher (I've only ever gotten about half way through it).
Good luck with whatever you end up doing.