Montana won't start and then wont shut off.

It all started with the van not wanting to start, you would turn the key and it wouldn't turn over. If you get under the van and start it yourself by touching the starter it does start however. This has then turned into blowing a fuze and also it would start randomly when trying to put it to the on to then climb under to start it. We figure that its something to do with the starter netural switch because when it did start on its own when in P or N it would keep trying to making the starter go off. Then it now will also not shut off totally. We have to disconnect the battery every night so that we can start it the next time we want to use it. You turn the key off and the doors do not unlock and the seat belt light comes on saying your not buckled and thats the only signs as to something different when you are turning it off (that and the battery being dead). So I guess my question is. Is this 2 issues like we think or could it be all one issue? And if so any guesses as to where to look to fix this! I want my van back!