Great input, thanks.
I personally like associating the proper units to parameters in my schedule, in case I want to use formulas for something. One used frequently is for VAV box airflows. Min airflow = 25% x Max airflow. You can even set this up in the VAV box family once, let it do the calculation to the boxes in your project, and then change it back. The Min airflow values will remain, but it will let you override if you want to.
One suggestion I have for your situation... Since you can change the column heading of a parameter in your schedule to whatever you like, I'd create a few text parameters called "Blank1," "Blank2," etc. If you have a column you want to leave blank, hide the actual parameter column and put in a blank one. Rename the column heading to say whatever it is your other parameter says, and leave them blank. Then, when you have the values, delete the Blank parameter from the schedule, unhide the proper one and show your values.
What do you think?