>>406085It's a generalization not a rule though, so double check online if you're going to buy a particular model, also plenty of DSLR's from way before 2010 had video as well, it just wasn't as common as it is today so don't rule out old camera's if you can get a good deal on them because a lot of them still have video.
Yeah the 30mm focal length is good, it's just on non full frame DSLR's there is 1.6 crop factor on the image sensor which means the 30mm focal length is actually closer to 50mm so it's not the same.
Regarding external microphones, most newer DSLR's come with a built in microphone but it's not exactly the best quality so if you really like good audio yes a "fuzzy" external microphone like this would be a good choice, and you can find them relatively affordable online (40-60 dollars)
