Hello, I'm Chris. Welcome and thanks for asking your question!
Are the shifts from park or neutral into drive or reverse harsh?
Are shifts 1-2, 2-3 hard?
Does it make an attempt to shift to 4th gear, if so does 4th slip or act like neutral?
Yes, all shifts are harsh/hard. From park to reverse it clunks. From ist to 2nd it clunks as well as 2nd to 3rd. It does not attempt to shift to 4th gear. Now it slips going to all gears causing the engine to tach high before it finally shifts. When on the highway going 60mph it will tach at 3000+ because it doesn't shift into 4th gear.
Since it is slipping in all gears this means there is damage already done internal inside the CD4E transaxle that is non reversible without an overhaul. The harsh engagements and shifts are most likely due to line pressure being maxed out from a faulty EPC solenoid. No 4th gear is most likely due to a:
Faulty trans control switch input
3 - 4 shift valve, main regulator valve stuck, damaged
There are both issues to cause no reverse but they would also result in no 1st or 2nd gears. Your transaxle needs to be removed and overhauled to address these concerns, there is not a simple repair that can patch and fix these concerns that have resulted in secondary internal failures.