Wow, it looks like I started quite a debate, and that was not my intention at all. I was initially just very thrown off to be told that I could just have a 15-30 minute phone call, which could take place in about a week and a half, and then we would have to set up another call if I needed more time. I worried that I would have to wait another week and a half to get more information.
As it turned out, I received an email from the investor asking if I would be available for the call today, instead. I took the call and did not feel any pressure to limit my questions. We did need to set up a second time to talk, but that's 2 days from now - so not a big deal.
I wouldn't say, at all, that I don't like the formality of the process. I completely understand the need to have an initial conversation so that everyone (investor and company) can gage the general fit. However, I would suggest being more clear in the email, stating that the process does include as much time as you need with a Senior Manager - that just happens after the initial phone call. It was disconcerting to receive an email offering 15 minutes (after telling the person on the phone that I had many questions), to send an email expressing my concern that 15 minutes wouldn't be enough time, and to then receive an email back saying that we could have multiple calls (and attaching a calendar that was booked for the next week and a half).
I understand now that the process includes plenty of time for investors to ask as many questions as they wish. If that had been communicated more clearly to me in the emails, I wouldn't have been nearly as worried. It wasn't the formality of the process that mattered to me. It was that, from what I understood, there wasn't going to be a way for me to have an in-depth conversation with someone in which I could ask all of my questions - and that was a 'red flag' to me. Knowing more about the process, I now feel like it was less of a red flag and more of a miscommunication.