Here are my findings
Control: Driver OR Passenger, Auto Targeting: none
Can use 'c' to heal or damage structures
Control: Driver OR Passenger, Auto Targeting: with Gunner
Can't use 'c' for either beam, no automatic healing of structures
Getting close to biters, does trigger either beam, though not sure what healing beam does to biter....
Control: Driver OR Passenger, Auto Targeting: without Gunner
Same behavior in remote control mode as with gunner
Here's the list of mods I've got
actual-craft-times-remade_1.0.5
BlueprintSignals_0.1.0
blueprint_flip_and_turn_100.8.3
bullet-trails_0.5.1
creative-mod_1.6.2
even-distribution_0.3.18
far-reach_1.0.1
Fill4Me_0.9.4
flib_0.5.0
helmod_0.11.16
informatron_0.1.14
LogisticTrainNetwork_1.14.6
LtnManager_0.3.9
mod-list.json
mod-settings.dat
Nanobots_3.2.10
OpteraLib_0.2.1
PickerAtheneum_1.2.2
PickerBeltTools_1.2.3
PickerDollies_1.1.4
PickerExtended_4.1.2
production-monitor_1.0.1
pump_0.1.10
RecipeBook_2.3.0
spidertron-extended_0.3.5
Squeak Through_1.8.0
stdlib_1.4.5
tape_measure_tool_18.1.5
textplates_0.5.3
VehicleSnap_1.18.3
WhereIsMyBody_0.1.3