248 EVs is not level 50 max (assuming 31 IVs). You should either have 244 or 252. Darmanitan also has 4 unused EVs. It should really be 4 / 252 / 4 / 0 / 4 / 244 or... I would just do max speed with 4/252/252 because one extra stat point in defenses probably isn't letting it survive much more.
Definitely Toxic on Porygon 2. When I used P2 on Subway, other than Recover, Toxic was the most used move on P2. Toxic and Recover work extremely well together for stalling.
I don't think I ever got over 56 on my Whimsicott/Smeargle/Espeon team. Last time losing was vs Toxic Spikes Drapion. I guess maybe that's why I should have taunt on Whimsicott. Heh, o well. I won't be having much time to play in the next short while. I'll see if I come up with something somewhat creative to try out again.