I chalk SS up to additional safety factor and move on. So yeah - I, for one, am just ignoring it. If I was closer to receiving it, then I'd run a bunch of numbers, and maybe bump up to a 5% withdraw rate if it made sense.
Personally don't have a pension coming, unless something changes.
Inheritance would just get added to the 'stache if / when it actually happens. Risk of something happening to where a 'planned' inheritance doesn't happen as planned too great to count that before it actually happens.