Multiple projects having same set of SDLC activities - how to automate this?

I have a typical situation here. In my company, the process is something like this:
(1) A user (from other department) raises a project requirement. IT department is the service enabler, and is supposed to design, develop and deploy.
(2) Portfolio Manager from IT then prioritizes it and provides tentative month in which it would be delivered. He may park this requirement also.
(3) Once prioritized, this project follows normal SDLC cycle until delivery.

My query: When a "Project" is raised, it follows workflow that I have designed. However, I also need to track efforts and cost spent. So I have to create "Activities" for each project. Now this is a catch. In my company, typically there are 100 small projects on average prioritized for every quarter. And many are raised but not prioritized. So creating activities for all these 100 projects does not seem to be practical.

** So how do I deal with such situation? Is there any better way other than "creating activities each time a project is raised"?
** Can there be a way whereby these activities are automatically created for each prioritized project?
** Can the portfolio manager have an option to choose which activities to choose from a list?

- enter not prioritized projects just as Tickets (requests)

Yes, I am doing this. So I have created a separate and shorted workflow for simple tickets. This flow ends when there is time for prioritization.

- when you need to plan wth activities, you copy a template into new project.
- you can design several template projects to fit several use case for activities list.

Template sounds interesting and I hope this will address my concern!! Can you please help me how do I do this?