Beginner here! Thinking about buying a DSLR. Searching for recommendations!

Philip Kendall wrote:

Partially - all (modern) DSLRs have built in overheating protection. Whether you hit that limit or not is dependent on a lot of things and can vary from one instance of the same model to another.

No. Under EU regulations, any device which can record 30 minutes of video is a camcorder and attracts a higher rate of duty than a camera; hence all DSLRs limit themselves to 29:59 of video. (It doesn't matter where you're located - the manufacturers have hard-coded this limit into every camera they make, no matter if it's sold in the EU, the USA or anywhere else).

A second point is file size: cameras are limited to creating files which are a maximum of 4 GB in size. If you're recording full HD video, you hit this limit in about 12 minutes (on Canon cameras anyway; I don't know about other makes). The most recent top end cameras (5D III, 1DX) have firmware which automatically creates a new file when this limit is hit, but older or cheaper cameras don't.

Pure image quality is generally much less significant for video than it is for stills, so as long as the kit lens covers whatever focal length you're interested in, I'd stick with it.

Taking a step back though (and as others have said), if your primary interest is video, you want to at least seriously consider buying a camcorder rather than an DSLR/mirrorless camera.