UConn usually schedules a solid non conference schedule. The problem this season is that a number of the teams UConn is playing are having historically poor seasons compared to how they normally perform, some due to injuries. Chris Jones was talking about this during the games over the weekend. Rhode Island often has an RPI in the top 100, last season they had an RPI of 75 which is much closer to where they normally are than this season.
Kent State baseball over the last couple of decades has been in the NCAA Tournament a number of times, and along with UConn they have won more games then any other school north of the Mason Dixon line. They are certainly a solid program.
I understand UC San Diego is relatively new to Division 1, but I have also heard that for many years they were a Division 2 power in baseball.
Other teams on UConn non conference schedule that are under performing this season based on their normal standards would include FIU, Bryant (another school that is normally one of the best in New England in baseball), and South Florida.
As for Big East teams, St. John's has had a very solid program over the years. They have taken a big fall the last couple of seasons, that's for sure.