#1
connect all over the fretboard?? like if ionian connects to any other mode like phrygian or aeolian
#2
well, they're all part of the same scale. theorywise that is.
ionian is the first mode of the major scale, then dorian, then lydian, etc.
so, yes, they all connect. if you wanted to move to a different mode in the same key, all you would have to do is start playing that scale with the next note in scale.
for example:
if you wanted to play in d dorian, you'd play a C major scale, but treat D as the root note. E lydian is c major, but you would tend to focus on E.
you'd be playing different modes of different keys depending on what chord you're soloing over. i'd get into more detail, but my theory's a little rusty.