Fealty is an interesting thing, it means more than just duty or service. Fealty can use a useful tool for sorting out conflicting opinions, Allowing you to focus on who/what's important.
But! Must be used with caution and in moderation too much focus on one thing can lead you too miss important event around you, this was a hard lesson for me to learn.
My fealty is simple
Anyone in immediate Need/Distress
My Knights Lady (or whom he/she favors)
My Kingdom's representatives
The Baron/ Baroness
My Local group
The general populace
Basically, it operates as a list of whome I can serve at any given time and allows me to choose where my service lies, its valuable and dangerous too much of anything is a bad thing, this includes service. If I followed this list religiously I would still be unarmed and unarmoured.
In Medieval times, an Armsman/Squire/Knight would be provided for by his/her liege so fealty was far more involved and demanding. A Bound knight/ squire/ armsman would live his life for the service of his/her liege. We can apply some aspects of this to SCA culture but must take into account the mundane world needs also.
Sadly or Fortunately, fully Period is almost impossible when it comes to fealty, the SCA is a game we play. I try to do the best possible to recreate medieval culture but unless I win lotto and can Hire an entire medieval towns work of labour and craftsmen, full immersion is not possible.
Just try day by day.