coverage questions

I have 2 questions, the first one is in cov. 3 it is very important to jam the inside recievers (#2) with your olb/ spurs, does it matter if you jam them inside or out? outside you have the corners, and inside you have the fs to funnel them to. Also, cov.2 is a great coverage and many teams run their base with this in college and in the nfl, but because you normally run it with only 7 in the box and the corners become run support you do not see it as an every down defense in HS like at the higher levels. If you are in a league where there is a lot of spread teams and a good mix of run and pass would you say that cov.2 could be run in hs as a base like what a Tampa Bay does or USC? Or would you say most hs teams do not have a good enough front seven to consistantly stop the run?Thanks in advance coaches. This site has been great for advice.