When do you suggest doing the content "there is 2 new scene in this version
talk to liane about tracy
go to rudy place , and talk to her , sure I'm in..."
Should I just follow along with the walkthrough and then do this stuff right at the end?
Well you won't get the Rudy scene unless you have completed the parts of the walkthrough that precede it.
In regards to talking to people (in general). most of those conversations start a clock (usually in days) that triggers a future event to happen. Most notably the Rudy and Neighbor track.
The Tracy track doesn't appear to be available yet so it really just informs you that at some point you will have to increase your friendship points with her to be able to use more Lust Magic on her. Not sure how much you need since you can use it on your sister who has about the same number of points. I suspect a future version will address the Tracy track.
And as far as the Walkthrough is concerned. You can do the events in any order they present themselves to you. But you will have to jump around the walkthrough to find the next event if you do it earlier (or later) than in the walkthrough. Perhaps later on I could make an addendum to the Day format I used and make a section at the end that tells you what the path is for each character.
The majority of the walkthrough though was made for the V4 version with the goal of getting the Brothel up to level 3 to take the Money Grinding out of the story. Once the Brothel is at level 3 needing money is no longer an issue.
At this point in the development you can complete every quest except the Upgrade Brothel to Level 4.