Hi!
In regular intervals, people ask me what it takes to run a large number of exit relays. Let me try to document a few steps that I think you need to take to become a Large Tor Operator (TM).
1) Think about registering a (non-profit) association. At least in Germany this helps with liability, and in general it helps to appear bigger than you are (and less likely to get raided). What we did was try and find a lawyer who would agree to "host" us inside his office. We succeeded, and now are a non-profit registered inside a lawyers office. How cool is that? :)
2) Register a fax number. At least law enforcement in Germany regularly uses the fax number present in IP records. We use a free German fax-to-email service, www.call-manager.de.
3) Register a phone number. The IP records should contain a phone number for abuse reports, and you don't want that to be your personal phone number. We use Sipgate One, a German VoIP service that redirects calls to cellphones and Skype for free.
4) Create handles for your organization at ARIN and/or RIPE. Example record: https://apps.db.ripe.net/whois/lookup/ripe/person-role/MB22990-RIPE.html With RIPE, it works far better, most abuse reports will hit you and not that of your upstream. Having your own IP records is a key element for abuse handling.
5) Find a good ISP. This is going to be a hard one. But not too hard. Go through forums and sites where ISPs posts their latest deals, and contact them about Tor hosting. We usually divide it into a two-step process: We first ask if they were okay with a Tor exit, and with reassignment of the IP range - no details in the first mail! When they come back positively, or somewhat worried, you can still explain that you are a non-profit superb large organization filled with security professionals, and that all will be good. The two step process usually helps in elevating your request to higher levels of support staff and without scaring them off to early. See also https://www.torservers.net/wiki/hoster/inquiry
5a) Still find a good ISP. A good ISP is one that offers cheap bandwidth and is not being used by other members of the Tor community.
6) Be quick in answering abuse. We receive a very small number of complaints, given that we run high bandwith nodes. I am actually still surprised how few complaints we get. Roughly 80% are automated reports, which we ignore, and for the rest it is usually good enough to send our default template. See https://www.torservers.net/wiki/abuse/templates and https://www.torservers.net/wiki/abuse/dmca
For police inquiries, we usually give them a one-liner (something like "As a German organization, we fully comply with Telemediengesetz §15 (the German telemedia law), which prohibits to log any user identifiable data or usage data unless required for billing purposes."). We get one policy inquiry per quarter on average.
What did I forget?