Waterfall is a waste on Swampert, as the Pokemon who you'll be using it on take significantly more from Surf. Swap it for Surf/Hydro Pump and go Relaxed.
This thing isn't mean to trap Blissey unless its 40-50%. Who ever said Duggy could lied. Ice Beam and Grass Knot are scary.
Well yeah, like I mentioned in your last RMT, you'll need to go Adamant to 2HKO. You just need to decide how important the ability to revenge kill Infernape is. Considering you have a Togekiss that can outspeed and OHKO 'Ape with ease, I'd certainly be going Adamant. You've mentioned Dugtrio as your counter to Metagross, Jirachi and Tyranitar, but Jolly Duggy won't OHKO any of them...meaning you'll be the one pushing up daisies.
Your Duggy spread is OHKO'd by unboosted LO Extremespeed from Lucario too, just for reference. Be careful about trapping him if you don't know the set (and lets face it, they're all SD variants anyway). The following spread ensures that you 2HKO Blissey, OHKO CBTar and and stand a very good chance at OHKOing Tyraniboah and AgilaGross. It also makes sure you survive Lucario's Extremespeed and OHKO him in return, whilst still keeping out in front of positive nature base 100's.
Adamant
248 Atk/ 48 Def / 212 Speed
Since you didn't take my advice on Adamant > Jolly last time, here's some calculations!
Jolly 252 Duggy EQ w/ CB vs 152/0 Metagross =
84.37% - 99.41%
Adamant 248 Duggy EQ w/ CB vs 152/0 Metagross =
92.04% - 108.26%
Jolly 252 Duggy EQ w/ CB vs 60/0 Tyranitar =
92.70% - 108.99%
Adamant 248 Duggy EQ w/ CB vs 60/0 Tyranitar =
101.12% - 119.10%
Jolly 252 Duggy EQ w/ CB vs 252/0 Tyranitar =
81.68% - 96.04%
Adamant 248 Duggy EQ w/ CB vs 252/0 Tyranitar =
89.11% - 104.95%
Jolly 252 Duggy EQ w/ CB vs 252/252 + Blissey =
44.96% - 52.94%
Adamant 248 Duggy EQ w/ CB vs 252/252 + Blissey =
49.30% - 57.98%
So basically, you're giving up a LOT of important power just to revenge kill Infernape - even though you already have an excellent Infernape revenge killer in Togekiss!