If you put up the priority too high you will probably lose updates to your event queue too ? Any GUi code will grind to a halt.
Unless you take over the whole system like in the Amiga days you can't be sure that you wont have interference, all you can do is allow for it, aim for less than 100% cpu time and know that you're doing so, so you let the o/s do what it wants to do when it wants to do it. You have to cooperate with it.
Also what are you going to do if someone is running some other CPU-hogging app on their system?
Unless you take over the whole system like in the Amiga days you can't be sure that you wont have interference, all you can do is allow for it, aim for less than 100% cpu time and know that you're doing so, so you let the o/s do what it wants to do when it wants to do it. You have to cooperate with it.
Also what are you going to do if someone is running some other CPU-hogging app on their system?