Be interested to see how you get on with this. Do you have a tight calf at all? Down the outside of it? What about the front of your leg? I had a similar problem where I thought it may be stress fracture, but the pain kept coming back after lots of rest. i researched and eventually came up with the Peroneus Brevis muscle that runs from the front of your leg round the back of your ankle into your foot. Lots of stretching and rolling the calf and front of leg seems to have sorted it!
I'm just coming out of calf probs. Rested for a good 3 weeks (whilst still going gym/circuits etc) the thing that's working for me is most definitely the rolling of the calf. With both a foam roller and a spikey massage ball (painful!!). The ball especially brings out bruising the next day, just like a deep sports massage. Stretches that I've been doing are just general walking the calves out in press up position and also hanging off the end of stairs etc to get a good solid stretch on the muscle. Good luck with the recovery - you'll get there.
Loads of circuits stuff you could do, mainly with free weights. At our gym we have battle ropes too, they're great to wear you out! Tyre smashing with a sledgehammer, sit ups, press ups. All sorts. Get inventive and enjoy.
I've done a lot of skipping over the last 3-4 years as part of boxing training, but to be honest, I see it as more of a way of warming up for a session, rather than using it to improve running. Can't hurt though, anything that gets you working will improve the stamina. Just concentrate on doing it correctly and not like some 4 year old girl in a playground jumping 2 foot high every stroke!!!