radiant heat - thermostat controlled loop balancing valves?

[syd]

I am installing radiant heat in a remodel. Part of the basement will be an apartment. Currently, there is only one zone for the entire apartment. There are four loops, each with manual balancing valves. My concern is that the tenant will want individual controls for different loops. I can allow them to monkey with the balancing valves, but it would seem better to have thermostatically controlled proportional valves on each loop withing the zone (some loops are in bedrooms, others in common areas). Is it reasonable and possible to control each loop with a thermostat? Are there any drawbacks to that? How does the wiring work so the circulating pump for the zone comes on when any loop thermostat calls for heat? Does the circulating pump have to run 24 hours a day? Thanks for any ideas or experience with this question.