A few suggestions...
1) I think a checklist is a good idea in general. It's easy to miss things/forget to ask stuff when you're having a conversation, I think we've all done that.
2) I agree with Ari's sentiment that you want to have a conversation and not just go down a strict list, but the two are not mutually exclusive. You can ask questions and take notes on a checklist form as you go.
3) I think what you might *really* want is an access control design guide, something where you can take the questions and then put that directly into a quoting tool. The particulars of this would vary with the systems you use, but it's something to think of.
In terms of designing and quoting an access control solution, these are some of the things I would want to know:
1) Do you (the end-user) have permission from the landlord to have the building doors modified for access control?
2) Why do you want an access control system (this *should* generate a decent discussion).
3) How many employees do you have, how often do you hire or fire employees or seasonal workers - this should help decide how many badges will be needed initially and also for an ongoing basis.
4) Tell me about your employees, business, etc. What I'd look for here is some information to help make a recommendation on the right style of badges. Should they be worn on lanyards, should you recommend badges with employee ID info printed on them, could it be worthwhile to recommend keyfobs instead of plastic badges and so on.
5) How many doors do you need access control on, do you anticipate this changing anytime soon?
6) Can you show me each of the doors - have the person doing the quote/walk-through take a picture of each door.
7) (more of a check than a question) Do all the doors currently open and close easily, without needing force? If not, there will likely be additional parts and labors to make the doors swing freely.
Also, check out our Access Control Job Walk Guide
1) Why do you need/want a video system? (has there been problems in the past, are there on-going problems, or are they just being proactive?)
2) Does your business type, industry, or insurance carrier require or recommend any specifics in terms of video retention time, minimum resolution, coverage, or non-coverage areas. I've sometimes been surprised how many places have non-obvious requirements around things. Ask up front before getting too deep in the design.
3) How many people will need to see live video and recorded video? Where will they be physically? How technically savvy are these users?
4) What are your expectations in terms of daytime/nighttime video and detail? Best to figure out upfront if the customer has reasonable expectations or if you will need to help them understand what their budget will get them.
5) Are aesthetics of the cameras a concern? Do you want them to be a visible deterrent, or blend into the surroundings?