What are you sequencing this with? Pam's? The Keystep Pro? Both?
That Erica Synths ring mod is very big for a case like this. It'll also be hard to find currently. If you know of one you can get and really want it, I can't stop you. I would definitely look at something simpler and smaller there. I'm a big fan of ring modulation as an effect that is well-suited to hardware and Eurorack, but you're trying to fit a lot of sounds and effects in a tight space, and that's space that could be used for attenuverters or something to control signals coming out of modules like the Pam's or the Pons without independent controls for all of them (I would say that's a bigger priority than more VCAs, which can be nice but is not always the best way to manipulate a signal). A module like the Doepfer A-133-2 or the Make Noise Moddemix would free up some much needed HP while still being valuable for both audio and CV processing (after all, ring mods are kind of just bipolar VCAs). I think this might ultimately be a more productive and playable setup than the Ringfade and the 2hp VCA. 2hp modules can be kind of a headache unless they're simple ones without knobs. Ultimately, it's up to you, but when I think that you already have the top row and you particularly want the other two sound sources, the Ringfade and 2hp VCA are the first places I would look to open up some room for a quality of life module like an attenuverter or switch or something else that helps you move signals and ideas through your rack.
The Otterly is not a bad choice. For 8hp, in a system this dense with sound makers and effects, an Ochd plus the expander is also worth considering (24 outputs with a good variety vs. 5 with a bit of flexibility). Either one will do fun and crazy things if you feed the one of the outputs back into the modulation input, so make sure to do that with whichever you choose.
I tend to think 1 sound source and one effect vs modulation and utilities is usually about right in terms of how to allocate space in a rack, but not everyone, including me, follows this in every rack concept. You'll have to decide as time goes on whether or not you've got the right ratio for yourself. Hopefully my suggestions either help you get where you're going regardless of whether it's the places I suggested.
You have an external mixer that can handle this stuff, right? I presume you do if you have the stuff in the first row, but it's worth asking. In-rack mixing is cool for CV and stuff, but unless you get hit bad with the special Eurorack mixer bug, I wouldn't recommend it.
