Yes on the plugs
In addition . . .
You do every single thing under that timing cover
Timing belt
complete tensioner assembly, every single part of it
idler pulley
all the cam- seals
crank- seal
looks like the water pump is also driven by the timing belt . . . do it, as well
skip any of these at your peril
You want everything under the cover to be good to go . . . and the only way to be sure is to replace it . . . until the next timing belt job
I’m assuming you’re planning on keeping the van for a few more years, correct?