Could it be okay to take viagra (sildenafil) with blood pressure pills and is it safe to take viagra (sildenafil) after a few beers?

Contact your doctor. Some blood pressure pills combined with viagra (sildenafil) can cause the blood pressure to go too low which could be deadly. Also alcohol can make ed worse so why would you want to worsen the problem with alcohol.
Depends on what kind. Of blood pressure pills, and what you mean by a "few." certain blood pressure pills which lower pressure by opening up arteries (minipress, hydralazine, isordil) can cause fainting from extremely low blood pressure when taken together with viagra (sildenafil) or the other similar meds. Heart attacks, strokes and death have occurred. 1-2 standard drinks are ok, but more can do the same thing as the BP meds.