Don't know a wholelot bout wheel building but I do know that 3 cross is the standard on most. Specially if it's a 36 hole hub. At least from the few things I have read bout it.
The rear wheel on my mtb is 3x drive side and 2x non drive (interlaced) My front wheel is a 2x(interlaced), both wheels were tension ballanced oringially too. These wheels have a lot of offroad miles on them and have taken some decent hits over the year. They have only required minor tweaking over the years. The wheels have rim brakes so the torque is different during braking than with a disc or drum brake and the rims are high quailty which helps.
I've seen plenty of radially spoked wheels out there both rim brake and hub brake equipped and combined patterns as well.
I think for crusising 2x would be fine with drum hubs.
I agree with Walker. Unless you are dirt jumping a 2 cross should be adequate. Proper spoke tension will make for a better build wheel than more crosses.
Glad to hear it will be ok. I was hoping I wouldnt have to buy spokes. I laced my drum hub up, I thought the spokes were long enough but I guess they weren't. I definitely wont be hopping or jumping, just riding the prairie path. Thanks for the help