If you make every class playable by a newb to good effect, vets are going to be overpowered and slaughter newbs with them even more than before.

IF people took the advice and tried assassins etc while they learn the ropes, they wouldn't be getting shafted in pk quite as much.

People don't start their racing careers in formula 1 cars.

Being a hidden class won't be a disadvantage in terms of preps, because YOU can still speak to other people and YOU can still choose to be visible when somewhere safe. And if you can tank (as assassins can, and rangers can) people will WANT to travel with you.

I completely understand why someone wants to be drow necro as their first character, but if you made drow necro work for a newb, a vet would take them and newbs playing other classes would be slaughtered.

Also, do you realise that gear and preps are already largely level based? For example:

Some preps can't be bought unless you are above a certain level.
Wands can't be used unless you are above a certain level (in particular, sleek wands can't be found until certain levels). High level weapons do less damage when a low level uses them than when a high level character uses them, etc.

And, just to plug assassins again, they are not gear dependant. Bannolic geared almost exclusively to keep the weight he carried down. His gear was otherwise very poor. Whenever I had a good weapon I lost it soon after by attempting overly risky.

What you seem to want is for gear not to make a difference, and that would kill off the mud for a lot of other people. It's not a "free win". It's also been shown that people stop valuing stuff if it is laid on a plate for them.