Wow you have a long question. I will try my best to answer your queries. Thanks for reading my books. I am glad you have found them useful.
Firstly, i think you probably find it 'conflicting' because some of the info in this Q+A were answered in previous years. And that's why the 5 Yellow, Three Killings, Grand Duke positions were in different sectors. My books, should be pretty straight forward and, to the best of my knowledge, should not contain any conflicting information. :-)
Here are my answers to you Qs:
1. You only consider your house's built-up. No need to include the entire land. BUT, the 3 killins and five yellow does extend outwards from your house's demarcation. So unfortunately, the answer is YES, it is best not to disturb the earth outside the West sector of your house. 2. No you do not need to demarcate your land to nine sectors. So don't worry. 3. Only as far as you can see. If it is really, really far away, like in your case, a few acres apart, then there's no need to worry. Only in the IMMEDIATE vicinity. Unfortunately, sometimes we could not control the actions of our neighbors. Hopefully, they began their ground breaking on a 'good date'. This would be negated. 4. It is best NOT to do this. But if you really have no other choice, the best is to select a good date to BEGIN the renovation. A good date means we select a time where the negative Qi is at it's lowest point and therefore safe to begin your renovation. You may find some answers in my "Personal Date Selection" book (http://www.masteryacademy.com/estore/itemdetail.asp?iid=90).
Hope the above helps.
Warm Regards, JY