I think this is what Blake is talking about when he writes 'a lot of the true technical challenges are on the bioprocess design side'. These are exactly as you say -- the 'creation of thick cuts of any tissue' includes getting the right cell lines and having them differentiate into the right things at the right time, having the right scaffolds, and putting things into the right bioreactors.
Yes, and in fact there is probably more work on this from the EA community than on a/cellular agriculture. Many charities recommended by Animal Charity Evaluators focus on plant-based alternatives and meat reduction in general, such as the Good Food Institute, Albert Schweitzer Foundation, and Anima International.
The ‘approximate share’ columns are the current split for traditional animal products, as of 2018! I’ll update the text below to make it clearer.