I was using ext2 for years on all USB flash drives AND HD drives.Of course, Reiner, I've already done that! Always ext2 for memory sticks, ext3 for harddisks. I split the 500GB HDD into 4 primary partitions, all ext3. With 4 Gb RAM, I see no need for a swap partition, at least not yet. Win 10 gone forever.
Lately I discovered some rough trouble on ext2 partitions caused by not properly unmounted SFS modules at shutdown/reboot. If there's such SFS modules it's drive can NOT properly unmount which is similar to a hard reboot by reset button!
A e2fsck returned a lot of wrong data in inodes and wrong counts in summaries. This was quiet heavy stuff!
I discovered this using BionicDog and checked all my Puppies (stored on internal/external HDs and USB flash drives) after that. The issue applied to all of them under ext2.
Since I'm using ext3 on all my drives/partitions everything just went fine!
So, I strictly would recommend: drop the use of ext2 definitely and completely.