1. In your PAF file you should have one record per person. You do not merge different people, just duplicate records of the same person. Yes, the record on the right-hand side is deleted. We add people on the FamilyScreen, not on the pedigree screen. You normally add children to an existing set of parents. You can add other parents for a child that already has parents (e.g. biological or adoptive parents). To do this click on the child and then click the Add menu and select Other Parents. Of course, this would only be done if the child really had multiple sets of parents.
2. PAF is a database program and Word is a word processor. Word processors are excellent for reports but inadequate for managing a database. Fortunately, PAF can create reports, charts, and books as word processor files. In the Charts and Reports screen, if you put a checkmark in the box beside "Print to file", then you click the Print button, an RTF word processor file is created instead of a printed document. When the RTF file opens in your word processor, just save it as a .doc file.
3. PAF Companion full version is just a printing utility that gives you some different charts and the capability of creating Adobe PDF documents.
4. Is it possible to EXPORT only one person with his ancestors from one .paf file to an other, existing .paf file? Yes, Export that person and his ancestor from the one PAF file as a gedcom, and then Import that gedcom file into the other PAF file. Backup both files BEFORE this operation so that if something goes wrong you can get back to your starting point. (Importing needs to be planned carefully to avoid mistakes.)