Looks pretty good for a 500 point army, altough I'd make a couple of alterations:
I'd ditch 1 fanatic and upgrade the boss for a black orc, as the heavy armor + shield makes him a bit more survivable. In the same vein, I'd make the boys 20 strong so I could put the boss somewhere else and still retain full ranks with them (it's good to have that choice). Then you could add bows for the riders for annoyance altough don't count them doing much. That's 499
btw
For additions when upgrading to 1k, you should decide if you want a bit of a magic or more combat characters, altough it's not a big investement to get models for both. Get a (night) goblin mage or 2 and get 1 fighting orc character. One thing to remember is, that you might want to mount your fighty orcs to boars at some point for extra save & mobility. Regarding troops and whatnot, one extra unit of standard orcs (you could do allright to make these 25 strong when army point size gets larger), one chukka and a wolf chariot or 2 would be a good addition I think. For addition to 1,5k you can add 3rd character, extra unit of fast cav and again extra unit of orcs. If you have the points, you could add some rare unit(s) at this points such as one doom diver or couple of pump wagons (or even a giant).
The 2k+ level is a whole different discussion then, as it offers a lot more options to be had.