I think you need to look again at what the whole range of VPX versions can offer!!  Not wishing to sound smug or condescending but what you are asking for, assuming I've understood your question, has been possible since before VPX1.

First, have you thoroughly checked through the range of transitions that are available "built-in"?  Also, if you right click on the little A:B icon that appears at the point where two clips meet, you will find on the drop-down list that appears e.g. "Fade through Black", which fades the first clip out to black and the second in from black.  Is that what you are looking for?

As to length of fade, on the same drop-down list I referred to above, towards or at its end you will see "settings"; click on that and a window opens which allows you to set the transition length pretty precisely.  Or you can simply drag the handle that appears on the end of first clip/beginning of second clip backwards or forwards to shorten or lengthen the transition.

I order to place titles between transitions, or more accurately, between clips, you will need to fade out the first clip (again that drop-down menu has this option), leave a small gap where your title can be placed, perhaps on a lower track, and then at the beginning of the second clip, drop-down menu again, "Fade in".

I hope that helps; if it does, please let us know: if not, and I've not properly understood what you're asking, please post back and we fellow-users will do our best to assist you.

Jeff