Ext4 is a solid choice for you.
I do kind of cringe that you are using ext2 on your root drive.
Starting with ext3 and now ext4 is the concept of transaction logging.
All fire systems are lazy and some more lazy than others.
That is say you delete a file or change it or whatever. The OS doesn't apply the change right now. It will happen when the OS has some down time. That's the lazy part, don't want to over-work that OS.
So, lets say you made a bunch of changes and moved some files and created a 30 page document and then the system crashes, for whatever reason. There are now a bunch of inconsistencies, files opened and not closed, changes maybe partly made etc. This can cause real havoc.
So, a journaling or logging file system has some disk space for file change metadata that gets updated RIGHT NOW.
So, when you boot up a logging file system the OS checks the log for changes and compares it to the file system and makes any needed changes and all is well.
This is why a modern Linux system can survive a power cycle (in most cases) without harm.
Ext2 is not a journaling/logging file system. eeks.
I am a fan of btrFS and zfs but I'm kind of a file system hobbiest. Ext4 is very good and way, way better than ext2 and it's part of the main stream Linux install.
As to the second part. I use MediaTomb UPnP media server and like it a lot. It's available to install with most Linux distros and even my Google Nexus tablet likes it.
It it's not on fire,
It's a software problem.