You do loose a lot of points for age. If they ever (they won’t) ask my opinion I would award extra points to the age group of 35 - 50 this is the real age group of most successful entrepreneurs. It’s people with years of industry experience, connections and savings to attempt creating a business. With all the safety nets and freedom Canada provides we should be encouraging people of this age group into the country under the rules of express entry.
Sorry for the rant but honestly it’s not just questions here but I get “a lot” of emails from very high achievers, people who are now looking at Canada after years in the states and find themselves unable to proceed due to negative points for age.
As for if this is a dead end, with a score below 400 and with everything we know that you mentioned it seems like there is a very low probability of ITA. Between the ages of 30 - 40 you loose 55 points. I don’t think PNP can help either, even if there is some program in a rural province you probably don’t want to go live there.
The following options do exist (not saying you should) just that they exist. Further studies in Canada and then PNP, Job in Canada then PNP, Provincial Entrepreneur programs (Investment Requirements) or the startup visa.