I know that this has been mentioned in other threads (and possibly this one) but just to reiterate:
When simming historical leagues, have the option of having real-life historical changes take place at the appropriate time. Don't FORCE this, as I definitely wouldn't want my 1972 Montreal Expos team to suddenly forcibly move to another country in 2005. But I'd like the option.
This would apply to, at the very least:
- expansion/contraction (contraction only seems relevant before 1900)
- franchise moves
- DH
- division realignment
- playoffs/wild-cards
- lengths of playoff series
- free agency
- free agent compensation
- arbitration (I assume this changed historically, anyway)
Although it would be nice to have a League Editor that would allow changes on an existing league, a simple checkbox upon setting up the league ("Allow historical league changes") would be a good start.