This is just my experience.
I'm American and my husband is Canadian. I have been visiting him since August and crossing every couple months to go back home (quit my job and got rid of my apartment by then). In November they pulled us over and held us for about an hour. at this point we had sent our application in but it was sent back because one of the forms had been updated. but we had a receipt that we paid our fees, our marriage certificate, and I did have proof then that I saved up some money to afford taking time off while the paperwork was being processed. However, I had no ties to the states other than living with my mother and grandmother when I was home. The border officer, after originally being a bit harsh, ended up giving me a 4 month visitor record and said that should give me enough time to get our paperwork back in so the border could see it when they looked it up. The visitor record did say "Not valid for re-entry" but the officer said because he put so much into our "file" we should have no problem crossing. We didn't get pulled over once and we crossed back and forth about 4 times in that four month period. The day it ran out (mind you, I hadn't found this board yet and was kind of clueless), we were on our way back from the states and told the officer we would like to apply for a new visitor record. He gave us a slip, they held us for an hour again, and finally gave me my passport back with no slip. Every time now that I cross we get pulled over. But we still always have those documents (and now have had our paperwork actually in since february) and I have never been denied.
So, what i would say is, you really can't ask for a visitor record. If you ask (like i did), depending on the border agent, they probably won't give it to you, but if you are just honest and give them all of your documents maybe they will. Pay your fees before you cross so you have proof that the process has been started, but i wouldn't go through all of the trouble of getting put on a lease or getting a job in the states unless you have some sort of record. That being said, I believe because I don't have a job or a lease it has made them pull me over more. Start the paperwork now, it's a very long road. The stress of the border is a shame when you really aren't doing anything wrong and just want to be in the same place as your spouse. We have recently stopped crossing so much (home is only 8 hours away from Ottawa so we'd go every couple months like i said) and applied for NEXUS thanks to computergeek.
Sorry this isn't much help, but thought I'd share my experience. I wish you the best <3