well, lower chest could possibly be hit if you switch up your benching style, like doing incline bench and decline bench.
It is also alot easier to target specific muscles in the pecs if you use barbells instead of the bar because you get more mobility.
As for your lower Abs you should:
1. cut any extra fat
2. Do leg lifts, leg holds
3. Do a lower body leg workout (it does help your lower abs)
4. have lots of crazy sex.