10 watts can usually do not much harm ( depends on antenna decoupling of both parties, how far are they appart etc. ).
But you are sketching 1st intermodulation products and these are in most cases not the ones to be worried about. Usually it are the 3rd order ( or higher ) products which can cause problems in the receiver passband of your translator. These are mostly caused by intermodulation in the final amplifiers of the transmitters, but can in principle be caused by everything which is not lineair ( even corroded pivots!).
Ok, the intermods you can expect.
2nd Order ( strong, but in most cases far away from your receiver passband )
2 x 93.9 = 187.8 mhz
2 x 104.7 = 209.4 mhz
104.7+93.9 = 198.600
3rd order ( weak but in most cases in the passband of your link transceiver ).
( strongest products only ).
83.1 mhz. ( 2 x 93.9 - 104.7 )
115.5 mhz. ( 2 x 104.7 - 93.9 )
So, i think your pretty safe, especially with your low power and all.
( i checked the higher order products as well and they are far away from the FM band ).
Just give it a shot.
Regards,
Evert