it's not a good idea for me !
1 : Having the DA*55mm make sense when the body is weather sealed, the K-r is not.
2 : the FA 50mm f1.7/1.4 is as good as the 55mm as long as you don't need weather sealing lense.
2*: the FA is far less expensive
3 : You have the K5 for 10 days, wait few more to know how to use it well, because i'm sure you didn't use it at its full capabilities
4: have you search on the web your Tammy / LV issue ? maybe it's just nothing, some wrong parameters ?
(edit : after some few research, it appears that this issue concern all brand including Canon and Nikon.)
5: How long have you wait after starting the HDR ? because it ask a lot of PP ressource for the body. You should do your HDR on a Computer, with either the Pentax software (wich process exactly like the body does) or some Photoshop / lightroom / aperture / else software.