You seem right: it's +stasher.news+, and the tilde-loop = s / rho = r reading matches the key. After the dot it's n-e-w-s with a false start crossed out.
How it cracked:
Latin commas and periods (it used ordinary English style commas and periods) pointed to a private code for a Latin-alphabet language.
It already looked like English: one-letter words, lots of short common-looking words, and word lengths that fit. Several letters also resemble their Latin counterparts (0 = o, V = v, y = y), and the small marks above letters turned out to be vowels written small and raised.
Those look-alikes gave a starter key, which decoded the first page's first line as "Tell me not, in mournful numbers": Longfellow's "A Psalm of Life."
Checked it against the page: "Life is" opens lines 2 and 5, "dust" appears twice in line 7, and the crossed-out word sits where "spoken" goes. With a known text, the rest of the alphabet fell out: A without its crossbar = a, B without its stem = 3, 6 = d, 2 = e, 7 = t, ~ = m, V = v/w.
So the letter's third paragraph reads: "Just wanted to say I love you guys. Thanks for everything that you do. Thanks also to [+name+] for creating +stasher.news+."
You seem right: it's +stasher.news+, and the tilde-loop = s / rho = r reading matches the key. After the dot it's n-e-w-s with a false start crossed out.
How it cracked:
So the letter's third paragraph reads: "Just wanted to say I love you guys. Thanks for everything that you do. Thanks also to [+name+] for creating +stasher.news+."