Perhaps you have not set up the settings properly and did not have photos from the iPad saved via photo stream to the Mac. My only complaint with iPhoto, was having to pay for the upgrade when ios 5 came out. Without the upgrade the iCloud photostream would not work.
My photos and video transfer automatically when I connect to power and leave iPad in sleep mode. I have no problem deleting photos from the photostream, my trash can is blue and active.
On the computer, in iPhoto, click iPhoto pul down menu, select preferences, turn on photostream, add iCloud account etc.
On the device, go into settings, iCloud or Photo and turn on photostream.
As I learned a long time ago, it's a computer, GIGO, stand for: garbage in, garbage out. There are many Help and tutorials if you aren't sure how to use a program, but don't blame the program if the user doesn't know how to operate it.