Thank you for your post.

I actually feel this is the sort of thing CSSU-Stable is for.
Stable - the "LTS" of Maemo.
I don't see the reason for the additional repository.

As long as CSSU-Stable will continue to run with the same UX as PR1.3.1 OTB, I feel another repository would be more work for little gain.

These security patches and fixes should run through the usual devel>testing>stable setup that has served us well in weeding out the bugs over the years.

As for browsing, I feel long term the stock browser would need to be replaced, from what I believe parts are closed which restrict any upgrades. As flash is phased out of sites we need a HTML5 compatible browser in the future.
In the meantime yes it is important to disable depreciated algorithms, especially as we have little alternatives to use.