solid state amp for merlin tsm's ?

mapman, fewer than a few percent of all amplifier manufacturers terminate their amps with a zobel. to be 100% certain, call the manufacturer and ask them if one is used.
best,
bobby@merlin

Has anyone tried the Merlin rc networks on speakers other than Merlins? Is there any harm in trying?

no harm in trying them, many do use them on other speaker systems.
BUT the merlin rc is designed to be as inaudible as possible on my systems. there may be a better micro tune for other speakers due to their specific characteristics and what you are trying to affect.
best,
bobby@merlin

If your preamp inverts phase and you reverse the speaker wire polarity to offset, do you reverse the rc networks also?

no, cap to positive always.
bobby at merlin