Re: Ishtikhara
Staying within the boundaries of deen meaning to stay away from the major sins and that which transgresses the limits of our deen. Also the isthikhara cannot be for something that is not permissible. Yes once you have made isthikhara and asked of Allah then continue to do so and put your trust and hope in him and whatever is best for you will happen inshaAllah.
If you have prayers to make up then you can still pray Sunnah and Nawafil prayers like Tahajjud.
And Allah knows best in all matters