That sounds like a reasonable plan. Just make sure the dump occurs before the daily backup runs.
I wouldn't worry too much about the incrementality, unless your dump files are quite large (consider using pbzip2 if that's the case). Something like rsnapshot or duplicity could help with managing old versions of user files, especially for the dreaded accidental delete.
Bonus points: consider enabling MySQL's binlog and look at the --master-data option for mysqldump. With this, you might be able to reduce the frequency of mysqldumps.
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