I suspect many a one confuses the spirit with the shape of the letters.
You do not need any kind of nib to write any script. You may need a specific one to make it look calligraphic, but letter forms will work the same whether written with or without line variation.
A nice thing of some italic methods is their stress on rhythm, which can make them somewhat easier if movement limited.
No need to expend a lot on books either. I would suggest having first a look at Operina.com, they have a reasonable number of free books available on handwriting with easy to start methods. Plus the first published one that got the style rolling publicly, Arrighi's Operina.
As for loops... that, too, depends on where one sets the bar for claiming 'italicity'. Soon after the first masters, new styles popped out extending serifs, adding ligatures and eventually loops.
As for paper position... I find it similarly radicalized. For calligraphy, it may be better some or another approach, which I will not discuss. For plain handwriting, anything that makes you more comfortable will do. Looking at copy books through the ages, one can find masters suggesting all kinds of angles, even close to 90 degrees, specially where school tables had less space or masters were less rigid, more sensible and more accommodating with student needs. So, just try and see which one works better.
Bottom line: for the OP. I guess that the most important is to find a style that suits your writing limitations, does not tire your hand, and then simply try to make it clear and consistent.
Beautiful line variation shapes may come later if, and only if, you feel like them.