Hey man! Always good to hear from other orkie players. Orks are the 40k army for people who love to win 50/50 but if it goes haywire you gotta have the sense of humor to back it up. Once you get the boyz down in 4th edition you’ll win a good 70% of the time. The choppa pwr claw nob works in that you have the option to use either/or but with both you get an extra attack. Once you start doing stuff like blowing up dreadnaughts, carving up marine command squads and generally just wreaking havoc you’ll get the idea but you do have to get the boyz into h2h. Also its necessary for when you’re running truck squads because they don’t have all the extra attacks that 25 troops would have fighting 10 space marines. So it compensates for the lack of troops.
A lot of the stuff you listed in your army people still do use. I have a fellow ork player who uses an army similar to yours with the addition of stormboyz and it works great. Gretchen still work great as a screen for walking armies but in my 40k ork armies I use custom force fields. Space Marines and all can target your units past the gretchin so they’re not getting picked off so I figured just make the boys fast and protected.
If you have enough foot sloggers you could probably run a decent army list with the troops using all that armor for cover plus some flanking trukks to take care of lack of speed. In addition you use a gretchin screen for your troops if you like. My friend uses the gretchin and it works great. He won our 1300 pt league at Gameworx in Baton Rouge with it.
Bikes are killer in this game. You put a nob in a bike unit with a power claw and you can take out just about anything on the board.