Nothing in the definition of manifesto has anything to do with violence or fringe movements, and I tend to think those connotations are found mainly among Americans, where the term is not commonly used except when referring to the so-called Unabomber Manifesto by terrorist Ted Kaczynski (and like documents) or to Marx's Communist Manifesto. Neither of them has ever gained much currency here.
Indeed, the latter was published originally as The Manifesto of the Communist Party, being a statement of the principles and objectives of the communists. That is what parties do, like those radical democrats in the BJP, the proletarian redistributionists of South Africa's Democratic Alliance, or for that matter the zany revolutionaries of the UK's Conservative Party. And even if those fluffy bleeding-hearts of Australia's Liberal Party no longer use the word for their document, the BBC does. (For the uninitiated, these are all major center-right mainstream/non-revolutionary political parties in major democracies).
If you are declaring the principles and policy goals of a (new or existing) political movement or organization for a North American audience, you might do well with platform, as Merriam-Webster says:
- a declaration of the principles on which a group of persons stands; especially: a declaration of principles and policies adopted by a political party or a candidate
Canadian and American political parties, with one or two exceptions, issue platforms. This is true not only of Democrats and Republicans, or regional entities like the the PQ and the PP, but also of fringe-y groups one might suspect of wanting to issue manifestoes, from the Christian Liberty Party to the Justice Party.
If you are not writing on behalf of a movement or organization, you might be simply presenting a plan, but without concrete policy goals and a way to achieve them, it is simply a set of ideas, which could be organized as a treatise, listed as tenets, declaimed in a proclamation, recited as a credo, or simply declared as a declaration.