Well, you are sort of mixing apples and oranges there.
First of all stop - clicks: Pentax lenses all have a little ball and a spring that lets you feel those beautyfull "tacks" anytime you move half a stop...
Most other older lenses do not have such device, and the movement of the f-stops ring is continous: an advantage i.e for videos, or if you feel like you need that third of a stop less/more.

The focusing issue should be related to fat got sticky or little points of dirt in the focusing helicoid... some gym should help, a good cleaning could solve...

About flares... well, you cannot compare such lens with most modern ones, nor with such lenses as takumars, that always shined for their coatings and have a more modern design of lenses and groups. So the simple answer about this is: lens hood!

How do you like the rendition of the lens, yourself?