I have both cameras and have been running comparison tests between the two.
First, don't worry about the articulated LCD of the D5100. You can just leave it in place like the D3200 and it will lock in.
I've set up both bodies in exactly the same way so even though I'm using fine jpg the photos will have the same settings as close as the menus allow. I use the same lens for all the tests.
The first thing that is obvious is that the menu choices are better on the D5100. One example is when setting noise reduction. The D3200 is either on or off. The D5100 gives you a choice of High, Normal, Low or off. The D5100 also has Long Exposure noise reduction On or Off. The D3200 does not offer this option. So do a little research comparing the menu options, especially the Shooting menu and see if there are any options missing on one that you may want.
Next is resolution. A normal photo showing on the computer screen without cropping appears to be a little sharper with the D3200. It is easier to see at 100%. I have been measuring lens resolution using both cameras and the D3200 will show higher resolution.
Noise. I think the D5100 has a more refined sensor. Up to ISO 800 there is very little difference between the two. From ISO 1600 on up the D5100 appears to have less noise, even if the D3200 image is down sampled to D5100 size. If you use noise reduction with both cameras the slight resolution advantage of the D3200 is lost and the two cameras now look nearly the same. One reason why I say the D5100 sensor is more refined is the noise pattern is smooth where on the D3200 it looks a little clumpy or color blotchy when looking at full enlargement.
As far as handling of the bodies there should be no problem with either body.
I don't set up my cameras to be automatic anything. I use aperture priority, AFS, single point focus, matrix or center metering, and choose my own ISO setting. I didn't test movie mode.
I like both cameras and both can produce excellent photos. I have uses for the articulating LCD of the D5100. I find an improvement in resolution with the D3200, especially when shooting raw. However currently I can only view the D3200 raw files with View NX2. If I could only keep one body it would probably be the D5100 but it would be a tough call. For a beginner I would recommend the D3200 first because of it's simplified menu and GUIDE feature.