TorGate:
All the 60MB are to the torservers, There are 2 tor exit servers with a Bandwidth limit: 14.6 MB/s, burst: 29.3 MB/s. Is this a god ide to setup bandwith limit to 30MB/s ?
Depends on your hardware. What is your avg. CPU usage? Would you add tor instances on the same server or on additional hardware?
You can see here https://atlas.torproject.org/#search/torgate
From the graphs one can see that these exits are relatively new (~1 month) and have been down recently (TorGate1 is currently not in consensus/down as of 2018-02-15 12:00:00 UTC).
And the bandwidth history show relatively small values <3MByte/s.
https://atlas.torproject.org/#details/2B5DE6C07B3C3641EC63F1951CB425456601BA... https://atlas.torproject.org/#details/120859427EBA459F096DD2256407DFD32D8BA9...
I would say, wait and see what bandwidth your current setup can use before adding more tor instances at the same internet uplink.
I hope you are not running exits from home.