I've done this one.. in general, there's always something to do the next day, you may just need to look around a lot. Either way, zoelius' guide has a different set of instructions, so try his?:
|1. Head to the town square and speak to Kiel to hear a rumor. |2. Then on the next day, head to the beach area (Dragon Lake) and speak toDolce. |3. Wait until the next day and then speak to Dolce. Then go to Leon Karnak. |4. Then on the next day, go to the clinic to see an event. |5. Wait another day and then talk to Dolce. |6. Then on the next day, go to the clinic second floor to see an event. |7. Wait another day and go to to the clinic, speak to Nancy and then head to the Town Square. Find Dolce and bring her to the Clinic. Once you're inside the clinic, speak to Dolce and Pico. |8. Then on the next day, go to the clinic second floor and speak with Dolce and then head to Leon Karnak for the last event scene.
Nope, but earlier is good, because having a child and access to a White Stone opens up some equipment options and by far the best accessory for your wife and/or kid. Only reason to hold off is if you wanted to see everyone's pre-marriage events, whiiiich is quite an undertaking.
If you want to see Venti in your wedding just finish arc 3 before you get married, checking the other proposal events is a good way to kill time i guess. Or you can marry and re-watch the scene in the wedding photo after you finished arc 3, it will show Venti doing the ceremony, i figured this out because in the flashback at the end of arc 3 it showed Lest with the tuxedo (im not putting that thing off, the tuxedo is the source of my power) when i wasn't even married until like a week/month before triggering arc 3 so i suspected that if i re-watched the wedding scene in the photo after getting Venti back it would show her, i was right.
The Ja in the name is pronounced as Ha FYI. Monster Hunter should just be called rule of cool: the series, and that's why you love it.