Hi Artz03,
With starting a new game with a townie family, it seems to me that it could mean that either your saved game is getting to large. Or that you maybe playing with custom content.
A few things to try are:
01.) If you've got custom content, (items not made by EA aka 3rd party content) or even items from the Sims3Store or the Exchange. Try starting the game without it, by opening the launcher, click the Installed Content Tab. Checkmark Run Game Without Custom Content. Then click the Play button.
As sometimes CC does mess the game up for whatever reason.
Removing Bad Custom Content
http://sims3.crinrict.com/en/custom-content-cc/bad-ccIf you do not want to do this with your main save-game, make a copy of it and use the copy to test-play.
02.) Try playing your current family(s) in a new game. -- This is different than moving them into a different house or moving them to a different town. Save the household(s) and place them into a new game to see if things run smoother from there. If it's still buggy, laggy, freezing, or crashing your game save might be corrupted. This happens from time to time and when saved game files get too large.
03.) Try deleting the cache files (socialCache.package, Sims3Logs.xml, simCompositorCache.package, scriptCache.package, compositorCache.package, CasPartCache.package)
-- Also delete everything except Ccmerged.package file in your DCBackup folder.
-- Documents > Electronic Arts > The Sims 3 > DCBackup
04.) Check your active household's family and individual inventories, as having to many items (100 or more items) in their inventories may cause lag and freezing. This can happen fast if the sims is a fisher, gardener, inventor or alchemist, not to mention collector.
05.) You mentioned that you just did a fresh reinstall of the game so try running a register cleaner program. (Something like Ccleaner, It's free -
http://www.piriform.com/ccleaner/download)
This helps clean up temporary files, internet cache files and other files that are left behind that are no longer being used, after uninstalling.
If this doesn't help, please post back to see if we can come up with some more tips to try.
MrsFlynn