If you want to measure safely in the board just get 5 open core current transformers, and depower the board and place one on each incoming phase then close the board up again, while leading the 6 wires ( you can common one side of the CT output leads no problem) and then outside you can safely have your 5 multimeters with 5A measurement ability to read the transformer outputs. That allows you to have long term reading, or even connect a recorder to each phase to see the usage pattern. As most of the loads are going to be resistive ( heating elements) and the inductive loads will likely already have power factor correcting capacitors on them to make them appear like 0.80 PF loads you pretty much can ignore PF. 5 transformers as likely your incoming is 277VAC 3 phase, along with a regular 240V centre tapped mains line for 120VAC appliances, seeing as this is the USA, elsewhere in the world you only need 3 current transformers with 230VAC mains. For safety short the CT outputs when not in use, or even just use a clamp meter over the line to get a 0-5A reading that you scale appropriately and leave then all shorted.
For fridge freezer motors you would have to look, and in most cases they are going to have a PF of around 0.8, so nothing needed. 3 phase motors used for extractors will likely not have any, you would need to see the manufacturer of the motor to see what they recommend for PFC and add it near the motor controller, which will bring the PF up to around 0.9 and reduce line current a little.
Lighting is the issue, as commercial fittings will have PFC, but cheaper residential ballast units will not have it, and adding PFC capacitors will improve the PF but increase arcing in switches. You probably would find that lighting is going to benefit the most from simply cleaning the lamps and fittings of grease and dust, which will likely be caked on them. Replace the failed lamps as well, which will make a big difference ( people do not seem to realise that a failed flourescent lamp that has glowing red ends actually is using nearly double the power of a lit lamp, just heating up the ballast) along with replacing failed ballasts with new ones ( buy good quality electronic ballasts, not the cheap ones from HD, go to a lighting wholesaler and buy a decent Phillips or VS unit), and replace incandescent downlighters with decent LED versions ( YT channel Bigclive for ideas on light efficiency) and you will make a difference.