His group already demonstrated some of the things you describe about the latrotoxin domain proteins. They talk about some other protein that might relate to these as well. We talk about it in the BMSB transcriptome paper at
2. I think you need to address convergent evolution in this case. It might not be convergent evolution (I can't tell from what you present). But if you don’t bring up and address the topic head on, you could set yourself up for criticism.
3. The literature is becoming riddled with LGTs from X to Y, where X was found first and Y was found second (or vice versa). But really there are probably intermediates in between. For example, you could imagine a gene moving from a eukaryote to a Rickettsia endosymbiont to Wolbachia, or something like that. So I would look at your text to see if you can clean-up any references to that line of thinking. One of the benefits to working on recent transfers is that it isn’t an issue! ;)