Interesting because no you cannot castle through a pinned piece but this is one of a small number of rule changes that I have always thought would be good.
It would add a nice element to the game if you could immobilise a piece that was preventing you from castling by pinning it.
@Santoy I had a long time opponent who thought the same as you but if it is not broken do not fix it applies here after centuries of global acceptance of the laws with hardly any changes such as the 75 move rule.
"If it ain't broke, don't fix it" is generally a poor strategy for anything and stifles improvement/development.
I think there are a small number of very valid rule changes such as this that would add reams of new middlegame theory.
For a brief period, after it was agreed that a pawn could move one or two squares on its first move to accelerate the opening stage, there was no en passant but this was introduced very soon afterwards when it became apparent that allowing a pawn to streak passed an opponent pawn that had reached the fifth rank was flawed.
I love many games and in many cases, they have been given a new lease of life by adding a new rule. For example, I loved Mastermind until I outgrew it but got several more years out of it by introducing the rule with my opponents that the person that set the 'code' was allowed to tell one lie.
@Santoy sorry that was in the 15th Century.
Yes it was. A new rule change is long overdue 
Fischer actually introduced a few rule changes, the most significant: making it illegal to write your move on the scoresheet before you play it - hardly earthshattering.
Yes I was informed of this rule change when I returned to chess after a 12 year absence and that I could not use a scorebook only a scoresheet. But these are rules, not the Laws of Chess.
No