I haven't run into any problems (yet) with replicating DML/DELETEs (WS and MSA); you may need to set the threshold pretty low (1 or 2) for you situation, ymmv.
I have run into a few problems with DML/UPDATEs (eg, invalid UPDATE statement sent to RDB when the primary table has a check constraint ... or was it a rule? *shrug*). Anyhoo, as a general rule I've disabled DML/UPDATEs ... enabling only in certain cases where I can verify that I don't run into the issue with invalid UPDATE statement generation.
Sorry, off the top of my head I don't recall any issues with 5185. While you could search solved cases @ sybase.com, you're not guaranteed of pulling up all possible cases relating to 5185. If Sybase tech support is suggesting other potential issues with 5185 I'd recommend you ask them to expand on their comments.
If you're running RS 15.6+ you might also want to look at dsi_row_count_validation (= off). This disables row count validation ... which may or may not be a good thing, ymmv.