RSS problems / validation

Hello,

I’ve got my site up and running, and under most circumstances my .rss works fine: i.e. I can import it into firefox, and sage, and all that good stuff.

But I’ve got a friend who’s trying to syndicate it, and it’s not working. Furthermore, when I try to validate it at https://feedvalidator.org/ I get the following errors:

# line 158, column 189: ‘utf8’ codec can’t decode byte 0xa0 in position 21298: unexpected code byte (maybe a high-bit character?) [help]

… l last week, and tonight we went to theirs.? We were expecting a decent .. ^

# line 28, column 3: content:encoded should not contain onclick tag (10 occurrences) [help]

]]></content:encoded>

The .rss file is at https://blog.sethwilson.us/wp-rss2.php. Any suggestions? Thanks.