Many open source systems are powered by Hadoop, which is handy, but a bit of a pain to get to work with a lot of the larger BI programs such as Cognos.
There is always security issues to take into account, but really if you aren't one of the Fortune 500 or a high-value target the issue of your service host being hacked for datatheft is very remote.
They don't usually have CMS, but ERPs like Pronto (Australia) usually have CRM features built in or as modules for sale.
Are you referring to auto/autobody repair or something like aerospace/aeronautics. Both have a lot of specialized ERPs for them and not much in common...
Cloud for BI makes plenty of sense-only the biggest companies have the on-site hardware that is necessary for all data processing that BI analytics entails. This way smaller companies can have access to the insights w/o making huge investments into hardware.
have had a lot of success w/ freshbooks. Really easy to use and designed for non-accountants who own their own business.