Considering transferring a Snorlax and Dratini before the event ends
Honest question, really on the fence if I should transfer or not for the extra candy. Common sense says no, but I don't think I will ever use them other than walking buddies. Could possibly trade if that ever happens but not planning on it anytime soon:
Snorlax: CP 1252, 71% IV (4/13/15) Lick / Body Slam - doubtful I will ever have enough candy to power up, have another high CP Snorlax with same move set.
Dratini: CP 572 84% IV (15/9/14) DB / Twister - I have one more higher IV / CP Dratini and I don't know if I will ever have enough candy to evolve another Dratini. All candy goes to powering up current Dragonites.

Answers
I transferred 2 of my 4 Snorlax, 2 of my 4 Lapras, and all but my best Dratini, during this event so far.
I have one dragonite with awful moves and only 800CP. Considered transferring him too but I still want a "living pokedex" so I sort of don't want to. Definitely would suggest transferring what you showed here though - no reason to keep the stuff if you have other/better copies and won't make good use of it.
I almost transferred my 1409 91% IV Snorlax because I figured he's too low to power up but since my 1696 has low IV and bad moves I figured it may end up being my best if I eventually walk for candies.
I would never ever ever ever ever transfer that Snorlax.
I specifically keep a "Team" of Pokemon in 1000-1300 range for powering up Gyms.
I can't tell you how many times I come across a level 7 or 8 Gym that the lowest thing is 1300-1600 and I can take my team and beat 3-4-5 things for 1500-2500 Presitage. 3 or 4 runs and there's room for me to pop one of my 2k+ pokemon on the top half.
Dratini on other hand i'd send to Prof if under 90%
I use whatever I have in that range that has right move set. It looks like this
2 Waters: A 1198 Starmie and 1256 Omanstar both with WaterGun/Hydro
1 Grass: Weepingbell I caught in wild with low IV so I would never spend candy to elvove but its right CP range and has power whip
2 electrics. a Raichu with thunderpunch and Jolteon with Thunder
3 Wiggletuffs (My defaults, 1 Hyper)
2 Bugs (For Hypnos primarily)
2 Hypnos (For Poison types)
I have 1 FireBlast (For Grass)
Since my goal is usually to beat anywhere from 2-5, I just line up the 1-2 of my lower ones to have a type advantage vs Gym.