1). As long as you currently have a BAK tonneau cover, the BAKBox will fit a 5.5ft bed F150 just fine. 2). The BAKBox should not interfere with a bed liner, since it installs onto the rails meant for a BAK tonneau cover. 3). The box itself is made out of FRP composite panels like the BAK Fiber One tonneau. 4). The BAKBox does not require drilling when using it with a BAK tonneau cover. If you're using it with a different tonneau brand or trying a non-tonneau install, then you may have to drill or make other modifications.