OP here. Thanks for all your responses, they helped me assessing on how I can get max output with least amount of work to quickly get online.

I will go ahead and create a static website, add some simple PHP to include header and footer on each page (either w/out any framework or Lumen) and apply some Zapier (or Netlify) magic to make forms work.

Once the MVP is validated, we might as well switch to some other framework or stack but for now, this is totally doing the trick.