I play from disks which allows me to have all expansions and store content loaded all of the time. As a builder I would find being restricted to a couple of expansions would be both limiting and frustrating.
There are plenty of mods to help with smooth gameplay but I would start with the basics. Does your computer have sufficient specs and a decent enough graphics card to cope with more than one expansion pack at a time ? Bearing in mind TS3 is now an old programme it might also be worth looking at your graphics settings. Both W8 and W10 computers may need some graphic setting adjustment to reduce both rendering and stuttering.
I would also recommend backing up your game regularly against the day when the computer challenges you and then says no.
