How Can I perform daily (Differential backup) with archiving bit resetting the target doing a weekly backup
By definition, a DIFF will not reset the Archive Bit. That is what separates if from an INCR. If you do a WEEKLY FULL, the Archive Bit should be reset then
I'm not sure what the number of restores has to do with whether you do INCR or DIFF, unless you have that many DR restores. You find last copy of the file before the time it went missing or was altered, and restore from that whethe FULL, INCR or DIFF
You may want to look into "Synthetic Full Backups" Do a Full, then special INCRs. Backup Exec merges the last FULL (or Synthetic) with the INCR, and the result is as if you had done a series of FULLs, this does require a lot of disk space, but sounds like what you are looking for