I think - if I understand correctly - that I would do a simple translation for parts 1 and 2. So, in an empty workspace, try following these steps...
- Choose Readers > Add Reader from the menubar.
- Set MapInfo tab as the reader format and select the Cadastre dataset.
- Click OK to add the reader.
- Choose Writers > Add Writer from the menubar.
- Set MapInfo tab as the writer format and choose a new folder to write to.
- Set Table Definition to Import From Dataset and click OK to add the writer.
- You will be prompted where to import the schema from. Set MapInfo Tab as the format and select the Property dataset. Click OK to finish adding the writer.
You now have a workspace that will write the Cadastre data to a new MapInfo dataset, using the Property dataset as a form of template.
If any attributes exist in the Cadastre data that also appear on the Property schema, they will get written out. Everything else will be ignored.
There are a few ways to do this, but I think my solution is about as good as you can get. You could use a Dynamic translation, but I don't see any point in that (unless you are going to run this multiple times and the Property dataset will change schema each time). The FeatureMerger/Joiner method mentioned in other answers isn't that simple because it doesn't define the output schema.
The one possible snag is that the Property dataset is empty. FME might not like that. Without features it might think there is no schema and you get an error when adding the writer. The simple solution would be to add a single record to that table. We aren't reading that dataset, just using the structure, so it doesn't matter whether the table is full or empty. That data won't get included, only features from the Cadastre data.
As you say, requirement #3 is really a different thing altogether. But, as everyone else here has mentioned, you can use a FeatureJoiner (or FeatureMerger) transformer to do this. Actually, given that the data is Excel, and you don't really need to read all of it into the workspace, I would use the DatabaseJoiner transformer. So create your key as a new attribute (StringConcatenator or AttributeManager > Text Editor dialog) and use that in the DatabaseJoiner to connect to the Excel sheet.
I found a reasonably suitable demo dataset so I put a short video together, to demonstrate the techniques above. I hope it is of use. You can find it here: https://www.screencast.com/t/tO1F3s3i