You can restore an iPad backup to an iPhone and vice versa. Apps that are not compatible won't restore, but everything else will. The reason I asked is older iPads had a setting where you could change the function of the mute switch to rotation lock.
It sounds like your settings are corrupted. You can try Settings/General/Reset - reset all settings. This will scramble your Home screen layout and reset all system settings to their defaults, but you won't lose any data. Make a backup first for safety.
Afterthought: I assume your phone is not jailbroken.