I'm glad to hear things are going better.

When you replace the diaphragm gasket, #1 make a mark on the top and bottom tube sheets (there are arrows to show how to match them up, but a magic marker line on them is sooo much easier to see). Then remove the o-rings on the shaft (take off the bottom one first) and inspect them. Have a cup handy, put the o-rings in it and also the nut's and bolts that you'll be removing to separate the tube sheets (the sizes ate 5/ 16" for the bolts and 3/8" for the nuts (15 pairs, if memory serves)). Then you can take out all the tubes and fully inspect them for tears and replace any that you need to (small tears can be fixed with a hot glue gun - but it's probably better to just replace any damaged ones). Also check the tube sheets themselves for hairline cracks around where the shaft goes through as these can also be the cause of DE going back into the pool). If you need help with the "E" clips that keep the shaft connected to the tube sheets - let me know.

I wouldn't sweat the little bit of DE bypassing the filter until you have the new diaphragm.