1. Avalon rail link
The rail link to Avalon is not part of the plan because not enough people to justify running regular trains. The previous government did a rail study into this link, bought the land then the project went silent and abandoned. The same happened with Doncaster and Rowville links, did the investigation and abandoned the project.
2. What type of electrification
Honestly have no clue which electrification to go for. You can have a look in this thread: https://www.railpage.com.au/f-p1978456.htm
Note; The objective to provide a plan for Geelong to have a proper city rail system for the future (30 years+). Light rail could happen very soon maybe 5-10 years as well as more bus services, rail duplication to Waurn ponds and keep land provision for future rail links. I compared the population of Geelong and its roughly the same as the population of Cairns.