I don't know where to gear either. Nearly everything my characters wear comes from handouts or PK. If I can kill the mob to get it, it sucks and I want to replace it as soon as I can. I'll gear myself up by around level 15 with 'basic' stuff, but if I get fulled at level 35 I'm likely going to end up regearing in nearly exactly the same set as I did at level 15 when I started my character.

Levelling - it's certainly hard for some classes to level, and while I did manage to solo a conjurer to level 27 recently it took a long time. It basically only happens quickly when I'm in groups. I find this okay because I'm spending all my time gathering gold and preps, using them up in PK, and spamming skills. I usually end up levelling up before I'd like to in the process of this. But if you do find a group of three you can fly up the levels. Levelling up always makes things harder. If you're not coping with the PK environment at level 25 you're not even going to know what's happening at level 40. There is one area where you can easily solo any mage class to the point where people will want to group with you

Gold. Takes some effort and ingenuity but once you have tricks it comes easy. Although I do tend to get 5x as much commerce exp as everyone else seems to (and they seem to get 5x the observation xp and I don't understand how). Basically you locate some items that are worth money, find a shopkeeper who will buy them and that you can kill, sell the items, kill the shopkeeper, get more items, repeat.

If you haven't got enough gold on you to run to a healer and heal up completely from 1hp if the need arises then getting that much gold is your first priority. It's much easier to gather a large amount quickly in the midranks than as a lowbie, and at hero some classes can get silly amounts, but it's still possibly to never have less than ten gold on you in the teen ranks. Again, it just takes a bit of effort.

Although I do think that mercs sapping xp is an outdated mechanic, and characters who just can't tank should be allowed to use them without taking an xp hit. Most mercs don't do all that much damage or have all that much hp and it certainly doesn't compare to having another player in your group. There are two mercenaries that I can think of which people use for PK but by and large the ability to buy mercenaries is a feature of the game that gets totally passed over.

Hope some of this was helpful.