as to product-ads --

product-ads (adwords) brand, trademark, or copyright
issues are flagged for words or phrases held by the
legal holders of the brand, trademark, or copyright --
the violation does not mean a trademark per se.

if a google-adwords account does not currently exist,
or adwords product-ads are not currently being used,
then products-ads may simply be disabled for the feed
and the feed re-uploaded:
data feeds -> settings -> set up advanced feed usage settings

otherwise, google may be contacted here.
http://support.google.com/merchants/bin/request.py?contact_type=item_error

product-ads issues may not necessarily
indicate anything is wrong -- but simply a
flag to hold items from adwords until someone
inspects the items for adwords trademark issues.

if an adwords account is currently active, then contacting an
adwords representative who is also familiar with your specific
google-adwords-account details and disapproval issues related
to brand, copyright, and trademark -- especially with respect
to product-ads in particular -- may sometimes help.

as to 5xxx --

all link url's submitted must be accessible by google
and return the proper response to google at all times.

if the web-server does not respond properly or
responds too slowly, at any time, then google
may flag the item.

seeing an item within a browser does not
indicate if the website responds properly
or fast enough for google.

if the website responds properly during google's
next crawl then the issue should resolve itself
within 72-hours or so.