Sounds like your program with your trainer is good and the weights you are using are correct.
You sound quite fit already and already do a good variation of exercise. BodyPump is great for strength. No, i do not think another day with your trainer would benefit if this is your program already just that i think maybe an hour is too long. I don't think reducing your cadio in favour of weights will give any benefit unless you want to build more muscle.
Periodising simply means that your program should progressively increase. Eg if you were training for a marathon you might start off by running 5 miles and gradually build up distance over a period of weeks/months until you reach your goal. (Including sprints and hills would also help you achieve this)
Hope this helps