Good you have a decent solicitor!
The service charges for the estates are called fleecehold" and many new homebuyers stuck with these are trying to get it banned. In the end the freehold of the estate will be sold on by Taylor Wimpey and the new owner could ramp up these ongoing charges to residents to provide and investment return.
Not sure if your town house would be a rush job as you didn't say what the current stage it is at.
However, July is beyond Taylor Wimpey's financial half-year so that won't be a reason for rushing.
My advice walk away and buy and older home. One built pre 2000 would be fine.
You can see what you are buying, get a full survey done, negotiate the price, have a front garden and off road driveway and not have to sort out a rear garden.