Hitting a slope wrong slows the game speed, or walls etc. Getting hit with a rocket or regular grenade can slow down a cappers speed or push them into a wall where they are forced to stop.
Chasers aren't usually directly behind a capper when chasing, also it could become a required legions skill to avoid said grenade (assuming they are relatively easy to spot.)
The only time you have a "hand full" of team mates at your base is if there was a mass death, the beginning of the game, or a standoff. Any other time you have 2-3 at your base, the stay at home has LOs to deal with, the chaser can take 1 capper if they feel like wasting their nade and the Hof has to focus on stopping the cap while under fire. Cappers come in twos often but theres always seconds of difference otherwise they'd interfere with each other so I'm not quite sure if your under the assumption the nade blast would last for awhile but I may be wrong. 1/4 - 1/3 energy is not that bad at all considering if you activate OD before the nade then it has no effect + when your capping your usually not on the ground you grab it and your in the air where your energy recharges enough to ski. The only change would be the possible need to change your return route
You should look to the beginning of this thread, second paragraph
Same goes for body blocking but there's ways around it, plus body blocking is in the air and stops you before you can od. For these to effective they would have to be tossed in the air at an oncoming capper and time so they detonate before the capper can activate OD or have them detonate on the ground by the flag as the capper comes in. This doesn't deny their possible influence if implemented properly, I think they are a good idea for diversity as well as giving cappers (and other positions) another skill to master.
I think if you have even a small portion (1/50) it will still activate so long as your touching the ground and have enough health.
Amen.