EMB-170 First Officer reported receiving multiple caution and warning messages; including landing gear malfunction; during cruise. Flight crew diverted and after landing; the aircraft was towed to the gate.

Narrative

Our flight was the first flight of our day with a XA:42 report. When we got the airplane all preflight checks were good and no abnormal messages were present. It was my leg to ZZZ [airport] and we had a non eventful take off and climb out runway XXL in ZZZ1 [airport]. After about 10-15 minutes in cruise at FL290 our EICAS cluttered with multiple caution messages and 1 warning message. Coincidentally at the same time at 280 knots our speed tape fell and Auto Throttles kicked off. We heard and showed an over speed condition. I corrected the over speed condition by bring us to 250 knots and the annunciator stopped saying over speed and began its Throttle" annunciator. We were unable to silence the aural annunciation. We had LG LEVER DISAG; LG WOW SYS FAIL as well as the associated messages with those failures. We ran the QRH; [advised ATC] and decided to divert to ZZZ2 [airport] as it was right in front of us. We worked our way through the abnormal checklist and prepared for a flaps full landing on [runway] XYL in ZZZ2 as per the QRH. As we had delay vectors coming in we cycled the gear as per the QRH and ATC confirmed it appeared down. We communicated with the Flight Attendants and had them prepare for landing as we had no indication the gear was down and locked. We touched down on XYL uneventfully and had the Fire Trucks follow us into the gate. After arriving at the gate dispatch let us know we had a replacement aircraft waiting for us to continue the flight to ZZZ. The crew as a whole were glad everything worked out and we had a non eventful landing. We received a text with information about what we could do next. We all agreed we were fit to fly at the moment and continue our flight to ZZZ. Our new airplane was loaded and fueled relatively quickly and we pushed back. As soon as we were cleared for takeoff we received a FLT CTRL NO DISPATCH EICAS message. We taxied off the runway and parked in a run up pad to take care of the message. After a lengthy reset procedure our Flight Attendants called and let us know there were about 5 passengers who were very uneasy about the Maintenance reset procedure and wanted to get off the airplane. The message did successfully clear. Coordinating with both Operations and Dispatch we decided to return to gate rather than continue the flight with those said passengers in mind. ZZZ2 operations were fairly busy and it took about 30 minutes to find us a gate. It was a very busy and stressful day at work for our crew. We were presented with challenges the EICAS had for us and had to keep in mind the aircraft's limitations. Looking back at this event I believe we had some sort of electrical failure leading to these messages. Working our way through the QRH for the root message of LG WOW SYS FAIL brought us to the decision of landing as soon as possible. I do believe we as a crew handled this situation to the best our abilities as we safely landed the aircraft while working through a highly abnormal situation.Unfortunately I have no suggestions to mitigate this event; as it was an situation caused by failure of the aircraft systems."