[Skills, house rule] Unaging and skills

[(E)]

I am currently chewing an idea over for a game where the default character is an unaging elf. The game will have a fast forward approach to history with a mini-campaign then jump forward decades (or more) structure.

As such time use and maintaining high skill levels are not ideal mechanisms to use. I was planning on dividing* the characters skill sheet into martial art style packages**. Now each character will have a list of packages they have been trained in (Say 10 at game start?) and from this list they can choose maybe five packages*** that they have used in recent years and one that they are focusing in/spending a lot of time on. Points are shuffled around appropriately. At the end of the mini-campaigns the players tell the GM what they have planned for their downtime and a new selection of recently used packages is chosen for the next mini-campaign.

Notes
- Improvement of package selection, level of skills in a package and number of active packages is a given.
- Elves should have some characteristics that differentiate them from humans in pointy ears.
- Packages will be grouped along the line of 1 Primary skill, 2 secondary skills, 2/4/8 support skills.
Quick example, the exact makeup of each package will differ from character to character, a noble may have artistic appreciation (knife) in their version.
Primary Skill Knife,
Secondary skill Armoury (knife), Fast draw (knife)
Support Skills Knife art, Philosophy, knife throwing, off hand weapon perk knife

- Other threads have covered skill levels with unaging characters and while the options of "Immortals have no urgency to learn skills", "they will spend all their time maintaining what they know" and "They learn with great breadth of knowledge so it takes longer (and lasts longer as a result)" have all come up I am working on a mechanic rather than a justification.
- When I get around to calculating the points etc I presume it will be a modular ability of some sort. Maybe 12 or 24 points in each active package (1/3 in primary, 1/3 in secondary, 1/3 support)

Are there any rules for remembering skills and for recovering forgotten skills?
What happens when the elf goes to talk to the 12th century scholar in Latin when the last time he spoke it Julius Caesar was getting his feet wet in the Rubicon?

Does any one have any input or ideas on this house rule?

*Probably 80% of the skills will fit, languages, knowledge and social skills are a bit more difficult to include.

**I will try to keep the packages similar with 5,7 or 11 skills (or sometimes perks) in each for mathematical reasons.

***Overlap is acceptable, i.e. a skill may be in more than one package.