It's worth fixing the scale issues. It's probably just a case of you having differing system units between max and daz. And/or using obj which is a shit format
Another way I've heard of systems interpreting mirroring is for the exporter to look at the UV face winding... so then inverted faces (facing -W) are interpreted as being mirrored.
CS4 should be the same speed or faster than CS2. If it's not, check your system - there have been a lot of problems with drivers and some turd (sic) party utilities.
i think there's an event system recode going on right now, so later on the ui will be having big changes (like custom keymapping and macros), but not right now.