I have 4 sheilos I would like to ask the Rov.
The first question is, should a person learn yiddish so he should be able to access more Torah in the future or should he just sit and learn Torah right now?
The vast majority of Torah is now available in Hebrew or English. Unless you have a specific Yeshiva or Shiur in mind for which Yiddish is necessary, you don’t have to invest your time now in learning Yiddish.
The second question is does the Rov think someone who is doing exercise on a treadmill should wear tzitzis or not?
If this will cause discomfort or soil his tzitzis they may [and perhaps should] be taken off for exercise.
The third question is that I have a non frum aunt who gets very insulted if I leave the room when she starts singing some goyishe song. What does the Rov advise me to do.
Try to divert your attention to something else, speak with someone else etc. and leave the room whenever possible, without being too abrupt. It may also help to explain to her why you are leaving the room and that it is nothing insulting to her.
The fourth sheila is that I have a very small amount of time to do my own learning outside of sedarim in yeshiva. I would like to know if the Rov thinks I should learn more halacha l’maaseh or should I Iearn gemara bekiyus.
In the regular sedarim of Yeshiva the main focus is generally Gemara bekiyus and iyun, so it may be worthwhile to learn a little more halacha. However this is a personal issue and you should speak with one of your Rabbeim who knows you for more clarity. Ultimately, outside of sedarim you should learn what you have a desire to learn and enjoy.