with the meter being potentially over loaded without any apparent
concern (and it didn't get hot AFAICR).

They will also be installing about 10KW of A/C soon - now should I worry!?



10Kw -- 43A at 230V yes you should worry!!
May I suggest you need a bit of rewire, ask your aircon supplier if they
want single or 3 phase. If you need a 3phase supply you need to ask for a
new electrical supply, and 3 phase is not a first DIY electrical project
particularly in the workplace.
http://www.eece.ksu.edu/~starret/581/3phase.html