Photography

I started attending photography classes with a successful photographer and there's couple of things I was apparently doing very, very wrong. I do not want to question the photographer knowledge, but more so just to ask for "2nd opinion".

1.Studio portraits should only be taken with aperture of 5.6 or higher.

Is this true and does the same apply for outdoor portraits? Most of my outdoor portraits were taken with aperture 1.4 to 2.8, mostly because of less than optimal lighting conditions and I just love this beautiful bokeh.

2. I am apparently supposed to use viewfinder only and not camera screen to frame the pictures, with both eyes open to see the model. Also taping the screen to correct the focus is a no-no.

I was usually only using the screen since I lack the mobility (really bad knees injuries), so I preferred moving the camera around instead of my entire body to frame the pictures, having eye contact with the model is also easier this way for me. The focus on camera is also often not perfect and being able to quickly "correct it" by telling camera where to focus is very, very useful.

3. Using tons of lights and equipment to get desired results. The photographer that leads the lectures is very fixated on complicating the scene by using multiple of expensive lights and giant reflectors.

Personally I don't own a ton of equipment, so I always look a ways to achieve things without resorting to that many lights and reflectors and usually I can find people being able to achieve those results with two or even one light, simply by adjusting the angle, distance or power of the light.

I absolutely understand that more equipment offers more possibilities, but I just feel like it's sometimes unnecessarily complicated by some photographers.

4. Having a large team of assistants. Last lesson we were split us into groups and had role assigned to each of us. Two people responsible for lights, director, photographer and so on. According to our teacher and the way he teaches us, having group of assistants is necessary or at least highly advised.

As someone who only ever worked alone (excluding the models of course) and plans to work alone in foreseeable future, I am not sure what to think of that.

5. DSLR are better because they are more stable due to their heavier weight, compared to lighter mirrorless cameras. Also apparently information displayed on mirrorless cameras is lagging behind compared to DSLR, but I am not exactly sure what he was talking about.