Matching fully balanced with unbalanced.

Sure. But its likely that the amp, even though equipped with an XLR connection, isn't actually processing the signal fully. If the equipment supports the balanced standard (and in high end audio most of it does not) you will run into a buzz problem, although that is easily solved. If the equipment doesn't support the balanced standard, you likely **won't** encounter buzz. I know this sounds counter-intuitive, but that's how it is.

other words, run balanced as far as u can should be beneficial you think? ...  yes, unbalanced amp is equipped with XLR inputs.  

I think listening is more important than topology.

While a true balanced interconnect is less susceptible to noise, a fully balanced amp/pre are not by themselves going to convince me to spend more.

I think all XLR interconnects are true balanced, rather components could be not even if they equipped with XLR connections.... I wasn’t trying to go chipper on my preamp..i just try to understand if it beneficial to go balanced as far as I can in the system chain if I have unbalanced amp at the end anyway.