I'm wondering why anyone would go for jump ships when you could just build gates everywhere?
Even at their most basic 180 day schedule, that is fairly quick.
Do both sides of a jump point need a gate for it to work?
What are the downsides of jump gates? Where jump ships can only jump equal-or-smaller size ships, and only a limited number, jump gates can, as I understand, transport any number, any size.
Why are jump ships so much more popular?
1. Yes, you need a gate on both sides (well, if you want to come back, that is, you can use a gate on your side, even if there is none on the other side, but there will be no way back, until you either build a gate on the other side, or a jumpship allows you to return.
2. Downside: You do not own a gate, i.e. anyone can use your gate (Yes, this means your enemy)
As you said, jumpship can only bring with it a limited number of other ships, so, if your enemy´s fleet has 3 jumpships that can each bring 3 other ships with it, the maximum initial force attacking your jumppoint-guards is 9 warships and 3 jumpships, which are likely to try to jump back to bring reinforcement ASAP.
You just said it yourself, there is NO limit with jumpgates. If your enemy has a huge fleet of FACs, he can jump in several hundreds of them. Or assume he has a fleet of 50 battleships and they all enter in the exact same second, blowing your JP-guards to smithereens.
Of course, you also show any enemy the way to your homeworld too, he just has to follow your jumpgate-route.