can two 10' wiremold with 10 outlets each be connected. If so, how and what would be used.

Yes. To couple two units together use the 2001 coupling (one coupling provided with each unit). For more details, please refer to the installation instructions sheet provided with the product. The installation instructions sheet can also be downloaded from our web site (link below): http://www.legrand.us/wiremold/raceway/plugmold-systems/2000-pm-steel-multioutlet-system/2000-pm-steel-multioutlet-system.aspx

yes

They can, but it is not a good idea. The strips are rated at 15A which means it tolerate the heat generated that current. At 120 volts a 15 ampere current generates 1800 watts of power, most of which goes to what is plugged in rather than the wires and connections. You will use the full capacity if ten 180 watt appliances are plugged in (or five 360 watt etc). When you connect the strips end-to-end the capacity is still 1800 watts because everything for the second strip still must go through the first strip. So now you can't plug 20 objects into the strips at 180 watts each but are limited to 90 watts each if all plugs are used. This may not be a problem for you who will remember the total can't go above 1800 watts, but the next owner or a spouse or a friend may not know that and overload the circuit. If you are properly wired, you'll then pop a circuit breaker but if not the wires inside will get too hot, catch fire or short to the metal jacket of the conduit. It can be done but you or your electrician must make sure no more than 15A ever flows in the circuit. That means it's own separate circuit breaker. There are small clips available for some surface mount conduit to cover the end where they butt together. The clip can be screwed or glued onto the outside of the joint and painted to match if required.