Don't forget that all performance data you've calculated is now completely useless as the charts (for the types I've flown anyway) specify full flap as part of the configuration.
I was also taught to use landing flap in any level of crosswind. I'm not sure if this happens to be type specific (C172 / DA42) as I suppose some aircraft are more of a handful than others, but I haven't experienced too much hardship in using full flap in all scenarios.