1. Basically yes, although I would centralise the breeding of mice and then farm them out to researchers as they developed each of the different cancers. Another option that we are not making as much use of as we can is natural cancer in human pets. We have millions of dogs and cats developing natural cancers that we could use.
2. Yes sequencing has not shown the promise for treatment that we hoped, but that is because the treatments we have were not developed with genomic data. It doesn't matter how much you know about a cancer if you don't have any tools to actually attack the weaknesses identified. We need to use the genomic data to indentify weaknesses, then use these identified weaknesses to screen for new treatments.
The best targets will be those genes that are not normally expressed in adult tissue that are expressed in cancer tissue. When I was an academic I had a student look into this area and there are literally hundreds of genes that are regularly expressed in cancer that are not expressed in adults. These are perfect targets for immune treatments provided you have enough of them to draw on.
3. Actually most newly diagnosed patients have deceptively great treatment options. For most cancers most of our treatments are just delaying tactics, not curative. Anyway for those few cancers where we have great curative cancers treatments are not the areas that I would start on.
4. Many people have tried to get funding in this area without success. You appear to know something about the funding process so you would know that any such grant would fail to get funded. Because of the needs for a proper animal model infrustucture it would not be possible to do anyway. I would rather concentrate on getting the animal models right before working on any new treatments.