Seeking Strum

Steve, you can do it in the PRV. You will have to move the start points of each note, but it's not as tedious as it might seem.
I just set up some reasonably convincing strums in a matter of minutes. Of course, familiarity helps, but you'll get there.
When you strum a guitar, you get the obvious timing difference in the individual notes. You also generally play the notes toward the end of the strum slightly louder.
The key to working with MIDI is to really listen to how the real instrument behaves, and use the tools at your disposal to duplicate that.
This reads much more complicated than it actually is. Just run with it, and you'll be fine.
Open PRV.
Zoom in so you can see one measure.
Set Snap To Grid to Absolute Time.
Select the Draw tool.
Draw your notes in at the first beat.
Now, change to the Select tool.
Drag the notes to the right as you progress through the strum (low to high) roughly 1/8" each. Your total strum will probably be slightly longer that a 32nd note, give or take.
As you do this, notice that the velocity view at the bottom of your screen shows several lines of equal length.
Switch back to the Draw tool, and draw a sharply rising curve over the lines, starting at about 40.
Now switch back to Select, and highlight the notes you just drew.
Copy, and paste as needed. You might want to change Snap To Grid to a  more precise increment at this time.
Repeat for each new chord.
Now, switch to the Track View.
Once you have a pattern established, you can highlight the track, and bounce to clip.
Then, right click in the track and enable Groove Clip Looping if you want. You can drag the pattern out to repeat as many times as needed.
hth

Good deal.
In the PRV, find the icon for Use Controller Pane, and turn that on.
You should see a second panel, below the note part of the PRV, dedicated to velocity.
For this scenario, I am working with MC5, which is derived from SHS7, so you should see the same thing.
I can post some screen shots later if it will help.