We should send space probe just like New Horizons Spacecraft to Eris. So we can launch this spacecraft in 2015 to make Jupiter, Saturn, and Neptune flybys then to Eris.
There haven't been any probes sent to Eris.
Any information obtained from any space hardware during the mission reaches earth by radio. (That includes manned missions as well.)
No. Eris is much to far away to send astronauts there. We have not even sent any probes there. The only object astronauts have visited is the moon, which is much closer to Earth than any other object in space.
No. No spacecraft has gone past Eris, nor are there currently plans to send anything there.
yes
none
None.
Nope, not yet and there are no plans for any to visit in the future.
yes lots of space probes
Eris has one satellite
Spirit and Opportunity are two.
Plenty - see related link for a list