G'day mar1234.
For your first question regarding windshield clear vision, your assumption about "if you don't read into it" is correct.
The question is asking what aircraft the equipment is "required" to be fitted to. The regs state that aircraft below 5700 that satisfy casa do not need the equipment, thus everything above 5700 requires the equipment and there isn't anything that precludes them.
There is also a difference between "aircraft" and "aeroplanes". "Aircraft" is a cumulative group (Remember the term "Category of Aircraft" in the instrument ratings/renewals? This can mean fixed wing or rotary wing); whereas "aeroplane" is aeroplane. The para 5.2 also lists helicopters below 2750 can get away without clear vision equipment, thus helping to narrow down the given answers.
The 2nd question is a little more confusing, and hopefully I can explain it clearer!
Para 7.2 states that press.turbine in cta must have an alerter. There is actually no way around this.
Reading thru to 7.3 it sounds like "oh hang on, if i dont have an alerter but have an indicator im alright". Nope... It is basically saying that any other aircraft that isnt a pressurised turbine and operating IFR in CTA must have an indicator.
Think of 7.2 and 7.3 as "stand alone" regs, not 7.3 giving a way around 7.2.
The simplest way I reckon I can put it is: "In CTA, Press Turb must have an alerter. All other aircraft, unless they dont have one, must have have an indicator."
Hope that makes it a little clearer.