I don't want to chance losing the first post info, so I'll post these links here for downloads from another site:
IPonlyrdy (stands for Island Paradise EP only - ready to play) - http://www.simfileshare.net/download/1806882/
IPallrdy (Island Paradise with other EP,SP, and store stuff included - ready to play) - http://www.simfileshare.net/download/1806914/
NOTE that there is now a mod that will keep NPCs from house boats around, so that will help tremendously with lag!
https://modthesims.info/d/665907/reduce-remove-lag-caused-by-houseboats.html
Continuation of previous fix suggestions:
Here's an example for the ports, which have routing problems and cause stuck Sims:
Houseboat dwellers and visitors will have problems accessing homes by boat at some ports: Port Primavera, Premium Port, Port Pleasant and Port Playa. Sims get stuck trying to route to a houseboat from a certain angle (from the left).
The easiest fix is to make these ports No Visitors Allowed (NVA). I leave the boats on these ports - Primavera and Premium - and I add a boat to Port Pleasant.
Block spots at the edge of lots that show uneven terrain with big rocks (and shrubs)!
Add trees and bushes (with rocks).
Romantic (Rubisel Ichtaca's) houseboat (FantaSea) needs rocks at the waterline and lot edge where terrain is uneven & remove two trees between the lots that block the road in town/world edit.
Put rocks where NPCs get stuck near Premium port (between Premium and Pretty Port on water/ground edge.
Place a NoVisitorsAllowed (NVA) boat on Port Pleasant. (Move or delete rocks too close to port exit stairs.)
Empty all other houseboats by evicting one family at a time and putting everyone in normal/land houses. Then, delete ALL those houseboats and their lots. (I kept the NVA ones for my active Sims.)
I did change some ports to port-less residences. (I see no need for three ports right next to each other.)
Thanks to Photobucket now charging for old pic links, I've simply removed the pics.