A lot of questions there. I would say first off, find a good SharePoint partner firm to assist you with the evaluation and migration. Preferably one with )365 migration experience specifically. Depending on your in house skill set, you may not need them there to perform the tasks, but having someone to lean on for planning, and project issues can be a life saver.
Safe bet to consider free o365 A2 as our production farm for SP 2013? No issues with capacity, performance and availability we should anticipate?
- No easy answer here, you need to do a risk assessment and determine how risk averse you are. What is your in-house expertise level, can you manage/monitor it properly, etc. For Capacity how is your 2TB split up - you will almost certainly bump up against their web limits, however I am not sure at the moment what those are.
If we don't know who the 500 users needing A3 are, how can we license?
- Best bet is to contact a licensing specialists. User licenses are not tied to a specific user perse, but you can't load up 1000 users, and swap them out, you have to define who those 500 users are, but you do not need to define them right away.
A2 does not offer 99% uptime. What will that mean to us?
- If it goes down there are no compensation options, neither is there an SLA for any guaranteed response times.
Data retention, backups and DR? Good cloud backup options?
- Again with A2, there is no SLA. It's not all that easy to get data back out of Office 365, especially at larger data points.
Should we worry about users storing and sharing sensitive and protected data on the cloud? Can we stop it? Can we inexpensively log and report on who accessed what across all sites and content? Can we trust MS to keep us safe? If not MS then who can we trust these days right?
- Always, but again this is based on your own risk assessment and profile. SharePoint has native logging and there are inexpensive tools that can format this data, but it counts against your storage. Large public providers also get hit with more requests for data from the government that they will comply with (and may already have government agreements in place). To mitigate that, you may want to look at a smaller provider, or a co-location service where you maintain ownership of all your data. That all being said MS and big providers want your business so security is a big deal with them.
Best way to get 2007 content up to o365/SPO 2013? I understand there are 3rd party migration tools (like Quest) that enable us to skip 2010.
- Depends on your requirement. If its is just data you can export and re-import it to O365 or use one of the 3rd party tools. If you have 3rd party solutions you need to evaluate if it exists in O365, there is compatible O365 solutions, or you can live without the functionality. Migrations, especially data intensive ones are never quick and easy, and there will be issues to resolve.