I don't think I'm seeing the page correctly--I see nothing in the blank area to the left of the remarks. If my answers are unclear, please send another pdf file with those areas darkened somehow. Thanks.
1) In the addition portion of this problem (the invisible partial products are to be added), the rules for placement of the operation sign in spatial addition should be followed, which state that the plus symbol be placed one cell to the left of the widest numeric symbol in the arrangement above the separation line. (NC Rule XXIV, Sec.178b) Both separation lines will need to be long enough to extend one cell to the left of that plus symbol. The multiplication portion of the problem should remain to the right, as shown in print, with the separation line extending one cell beyond on the right side as well.
2) This is certainly an interesting problem. First of all, do not braille the examples side-by-side as they appear in print. The layout of each example will fit just as it appears in print if you arrange the examples vertically. The problem with Example 1 is that the minus signs are printed in the subtraction portion of the layout. This means you need to allow for that column in the vertical arrangment, so the 2 in the hundreds place of the dividend will have to be preceded by a space. This goes against NC Sec.180b, but follow that rule and keep the division symbol unspaced from the divisor. Supply a general omission symbol after the negative sign that stands alone near the bottom of this problem. If the print page is shaded to show other missing digits (I can't tell from the pdf file) then supply more general omission symbols. The remarks will fit on the same line as shown in print, without runovers.
The down-pointing arrows should ideally be drawn as a tactile graphic. A second choice would be to explain them in a transcriber's note before each example. The first one could say "A down-pointing arrow is drawn beneath the numeral 8 in the dividend."