Depends on the TV. It shouldn't be less than 10 ohms, but it's normal for the resistance to be relatively low. It seems you've been stuck with the same problems for quite some time now. I'll try to make this as clear as possible:
If you're getting < 10 ohms to gnd on any of the power lines you have a short and you shouldn't be trying to turn the system on. It's normal for the 1.15v to be around 30 ohms. If this is the case, disconnect the wires from the regulator board. If you still have the short, then you need to sand the Wii board more. If it goes away, test the resistance to gnd on the voltage lines on the regulator board. If you have a short on the regulator board, then you probably messed something up on there.
If you have no shorts and the board still won't turn on, it's most likely the U10. When the system turns on, check the voltage on the pin with the wire on the U10 chip. If it's not reading 3.3v, then the U10 is not connected well or it's broken. It's either not getting 3.3v on the input pin or the 3-pin glob is not connected to gnd. If the pin with the wire is reading 3.3v, then it may not be connected to the via on the back of the board well.
While you're testing this, have a piece of magnet wire connected the reset via to gnd so you won't need USB. Hopefully this gives you enough to try to get it working.