the way you will control wet/dry in your rig depends on how it is configured and will be based on your experience/preferences. So expect to do some of the usual test & tweaking as any new unit requires. Most H7600 presets don't have dry sound control in the algorithms. Those who have it may require you re_store the preset w/a setting that will work for your choosen configuration.
In general I like to control dry/wet outside of FX processors, so having a Switchblade it'll be easy for you.
I don't see any problem in using the H7600 slaved to the Tascam mixer.
The H7600 has no ADAT ports. You'll have to use S/Pdif or AES-EBU. Both will work fine, even though S/Pdif is not professionally recommended for 96KHz sampling rates and AES-EBU should be the choice. At 44.1KHz both will be ok.
all the best