Hi Marty, at the moment there are many Pokemon in the lower tiers that should belong to higher tiers. Thus, I suggest having full tier shifts and starting 3-month cycle from February to May, or even quick rises only on 1 Feb, will allow these Pokemon to rise to the tier where they belong, thereby better reflecting Smogon usage-based tiers as a whole.
1. Public avatars are based on actual Pokemon characters; if there's no character that fits the bill you're not going to see it available.
2. I don't make avatars, I figured that was clear from all the "courtesy of [artist]" in those new avatar posts.