It's an interview or position had been offered to you?

There's no need to glorify the boss. Even if he's head of Fortune 500 company or has 5,000 staffs under his belt, he's still just another human being that needs to eat, sleep and rest. Take away someone's money, title and fame - where does that leave him?

His achievement is great, but personally whether someone impresses me it would be his/ her capability of a far vision, to mentor, lead, groom his subordinates.

IF you had been offered the position, ask yourself the ultimate question of whether you'll do anything to stay on the job (ie. fast pace learning, capability to catch up etc).

I think you misunderstood her context.

Big companies have secrets. Even bigger companies have bigger secrets. So she meant that if you're someone NOT from the industry/ background, nor remotely qualified for the job but was offered this silver platter all of a sudden, just be careful that it might not be what it seems. Don't assume only unknown/ small companies do the dodgy stuffs by the way. Well known or not isn't the issue here.

View this offer through a neutral lens and see if its reasonable for them to hire you with your background and experience. If something feels off, don't ignore the red flags. Just saying.

Seeing this part again makes me find it rather tasteless. HR is supposed to be the bridge between top management and employees, and they should be more independent in managing the stakeholders. Yes, they need to comply with management's direction and decision where its right, but also be neutral in assessing most of the situation to move towards mutual benefit.

If HR blindly follows everything the management dictates, it is weak and pitiable. Yes, the pity goes to the employees. Think twice again, that companies like this would mean they want to hold ultimate power by hiring executioner in the HR, who would just follow everything the top mgmt says. This somehow reflects a part of the culture in this company.

A lot of key positions vacant could be both a red flag and/ or opportunity. May have been restructuring due to scale-down, or the company went through an internal political turmoil, or going through some financial difficulty. Either way, if you're really keen to work for them - do your own digging into this company. If you're in the same industry, it wouldn't be too hard to sniff around for some unofficial news as reference through other vendors or their associate partners etc.

In your mind, match the "rumours" you heard vs what the interviewer answer you during the interview session. Its only fair that you know about the company as well because you're putting your rice bowl onto them; so as a prospect, you do have the right to know about some things to a certain extent.

I've worked with multiple type of bosses in x years of career in different companies - reporting to both business owner and also non. At the end of it, business-owner tend to be more calculative while non-business owner although need to take care of overall profit & loss, they're less of a penny pincher. Non-business owner boss shares the same fate as you, and are more likely to emphatize and be less calculative on certain things. This is based on personal observation and experience, may or may not be relevant to your case.

Just do lots of observation and see what's your 'gut feel' during and after the interview. All the best.