Stereo & Electronics - Will it work for long? 10inch on stock amp

I got a DS stealth box with a 10 inch kicker comp. Im saving up for the amp and the rest of the installation stuff. earlier i tried running it with power supply from the Sail panel midbass drivers, and it works well, kicks pretty good, not great though. Is there any chance i am harming the monsoon syster, or the sub itself?? i'm going to do it right eventually, but in the meantime is this ok to do?

Depends on how hard you try and run it and how it is hooked up. If you try and push it too much you can potentially clip the amp and do damage to both the sub and the amp. Generally it's one or the other and not both though.
How so you have it hooked up right now? It's important because if you have the wrong ohm load on the amp you can damage it.

i disconnected the blown midbass driver, spliced the connector and ran the same guage wire to the sub in the rear

From just one side or both sides? Did you use both pairs of wires on a DVC subwoofer? Need a little more to go on.
If you used just one side (both pairs of wires on tha side) and you are using a DVC sub on that side you are sending about 45-50watts (maybe) to that sub and it will be ok. Not going to be very loud or anything but it isn't overloading the amp.

im running power from only the passenger side sail panel. would running power from both have an advantage??

If you ran another sub then yes but the way it's set up you really couldn't do that unless you had a quad voice coil sub but that would then blow the amp due to lowering the impedance too much.
Leave it as is for now and it should be fine but I wouldn't push it real hard. Again, your only sending that sub about 45-50watts RMS and pushing it too hard would put too much on the amp.