Hello Mihai,
you can do this: add a grouping (Group1) to the form, add the table columns to this group, and set the "Group" property to Vertical (see screenshot 1). In this case, all columns will be displayed vertically and it will be convenient to fill them in (screenshot 2).
In your case, you can move some of the attributes to one group, some to another, it depends on what interface you want to design.
On the second question: you can use the "Width" property, for example, to make the field width as needed (screenshot 3), but this is difficult to recommend.
The fact is that 1C itself selects the size of the fields depending on the screen size of the mobile device. If you set the size of the element in absolute value and it is displayed correctly on one device, then it may not look very good on another mobile device.
Aleksandr