When I have trouble getting to the BIOS screen I find that holding down the Fkey that is required before power on seems to work UNLESS there is some hardware failure. And yes I don't let up until I see the BIOS screen.
The Acer only uses a few Fkeys so why are you trying other than what's called out in the documentation?
When I start my laptop the phoenix bios screen comes up and the blue progress bar stalls and freezes. I've tried different F keys to no avail. I pulled the back and disconnected the cmos battery for a minute and that worked but it is doing it again. The case wont stand up to me yanking on it every time I need to use it so I need a more permanent solution.