Unable to reach full boil?

Just as the wort was boiling for my Oktoberfest-style ale, I had to shut down my propane burner by order of the land lord due to county fire laws. Therefore, I was only able to put my 44 quart kettle on...get this...a propane barbecue grill. Because of this, for a straight 90 minutes I could only achieve temperatures hot enough to make it stir and roll about but not hot break.

Right now it's on it's third day of fermentation and chugging along fine at an O.G of 1.045 (was aiming for 1.051, but without evaporation...it was impossible). Should I be worried about the final product if I was unable to achieve a rolling boil?

You say it "stirred and rolled about," was it boiling slowly? If it was I wouldn't worry, but if it was only simmering, according to the "big they" you might get DMS flavors, but just wait and see! I certainly wouldn't worry too much because you can always make more if you don't like it (if you find a way to boil it, that is!) , and it might still be very good!

It might not be as clear as you wanted, but it should taste OK.

As long as you didn't have a ton of Pils malt, I don't think you have to worry too much about DMS.

You might want to look into a heatstick or two, or adding a 220v element to you boil kettle, if you have 220v available.