Hello, I have a similar job as freelancer for another employer sending 1 million+ daily. I do for more than a year I have learned a lot on the way the best practices to do this job. I know almost all of your duty list: installation and setup of IEM and PowerMTA, rDNS, spf, dkim setup, multhreading addon, dealing with hotmails, gmails, manual powermta log processing, etc. The only thing I have to research is to enable DMARC. I know also good VPS providers, cheaps and good emailing tolerance.
If you need to send every day, also need a regular support to monitor IP reputation and blacklist delisting, because this is manual work. Including the log processing and PowerMTA possible reinstalations, this could take almost 4 hours daily and that is my offer based. Hope to work together. Regards