1. ST7920 module has same physical dimensions and outline as standard 1602 LCD module, but has 132x32 pixels resolution and larger physical area of pixels (less wasted space, compared to traditional 1602 displays). This means that it can display up to 18 characters x 4 lines using standard 8x8 font matrix. You can have a look here (The slow drawing is animation effect, using LCDOUT it is possible to update whole screen at approximately 20fps rate):

Regarding the 25 euros, I don't know where you buy them, but I bought nextion on taobao, the basic model, for about $11. ST7920 LCD module is about $6, standard 1602 LCD module is about $1. OLED 1602 - also $10.

2. Your iphone, your issues. I like my devices to be fully accessible and have as few disabilities, as possible.

3. And where store graphics, sound files, etc, without SD ?

4. I don't see any instant boot times, with empty code - maybe.

5. I have tried it by myself, several times, several versions. IDE looks like monkey's drawing - visually they tried to emulate visual studio, but they didn't went into internals.