Should I remove chipped lead paint from door frames or seal and paint over?

I am not sure how we survived back when we would sand lead paint prior to using masks.

I see what appears to be flakes on the lower corner. If the loose paint is not removed the problem will come back and additional coats of paint on the door can also cause more problems if there is any rubbing.

Scraping or sanding with proper precautions would be the proper way to fix the problem. I would use a combination of the 2 methods.

If the top layer of paint is peeling/chipping away, it will probably continue to do it over time and you'll be stuck repairing it in the future. Getting rid of the problem would be your best bet which was my over cautious sister's approach. I used CitriStrip and also some Peel Away to remove all the built up paint right down to the wood. No sanding was required to remove the paint, just wiped it off after letting the paint remover do its job. No fumes and no airborne particles. We were then able to finish the wood with a stain and it turned out great.

Respectfully, asking a rather vague question will probably get you irrelevant replies. "Best" and "safe" are subjective terms.

What are you ultimately trying to accomplish, and how picky are you to details? How discerning is your eye? Sanding wouldn't be a good idea, unless you have some kind of dust extraction system in place, and everyone involved is wearing the appropriate PPE. Does dried lead paint give off any kind of harmful gases/radiation, especially when it's been covered up with other layers of paint?

If the paint is just on your trim, then I would be inclined to just replace the trim and paint/stain the new stuff. It's an alternative that is quicker than sanding/scraping, and it is less of a mess than using chemical strippers. Will the chemical stripper have an adverse reaction to the lead paint?

You should also be aware of your local ordinances. Some municipalities/govts., ie. California, are very strict on these things. If they find out, they'll probably want to get involved and supervise, so to speak. Now that you know the house has lead paint, unless you remove it, then you might have to make that disclosure should you decide to put the property up for sale. Asking this kind of question can open Pandora's box.

Obviously, just painting over it will get it back to a single color, but you'll be able to see the various breaks of the underlying areas, unless you apply numerous coats, building up the top layers, which is time consuming and requires more material.