Sounds like combination of shifter bushing and K1 spring problem. Poping out of the gear could be shifter bushing issue, is it your transmission lever to loose?
The second issue of not doing up-shift or flaring could be the K1 spring disc issue, a $15 part and 1-2 hour of labor should fix this. Do a search on both of these topics Here is link for K1 issues
http://transmission.articles.mbz.org/k1/
Good Luck.