Sell off to buy new covers?

I haven’t really sold off many characters since the first week of playing; have 16 spots pretty well filled.
But I’ve pulled a bunch this week.

Ares: maybe 10 covers so far?
Cap: 4 or 5
Modern hawkeye: 2, expiring in a couple hours.

I’ve sold off so many cap and MH covers it’s ridiculous, but with hawkeye looking to get buffed soon, should I sell these? Or get rid of my 5/5 level 1 Venom who is just sitting around?

And what do you guys do? I haven’t really sold off many * folks! still have iron man, storm, mbw… Then I’ve got some villains, Doom, Loki, Hood, Rag, CMag, and then the everyday covers; CStorm, Thor, Wolv, OBW, Hulk, punisher, spidey;

Does anyone keep a guy like im35 around?
I never leveled mine past 20, and like i said, I never invested anything into venom. I’m thinking those two should get lost, just taking up space?

I would definitely keep Ares and get rid of Venom or IM35.

There are some characters that are frequently needed for missions.

If it’s a 2 or 3 star hero, they will frequently be required.
2* Hawkeye (Modern) and Captain America (Modern) both unlock a lot of missions.
2* Black Widow (Original), Wolverine (Astonishing X-Men), and Thor (Marvel NOW!) – I haven’t seen them unlock missions recently, but they’re great characters.
2* Bagman – the worst character, and doesn’t ever unlock anything.
3* Punisher, Iron Man 40, Hulk – unlock lots of missions.
3* Spiderman, BWGS – I haven’t seen them unlock missions, but they are two of the best characters.

The 2* and 3* villains don’t seem to unlock any missions, but they are used in a lot of tournaments, and many are good characters.

Of the 1* characters, only Storm (Modern) has good utility once you have a roster of 2 and 3 stars.