It sounds like you were trying to construct an a-priori conlang, in which the meaning of any word could be determined from its spelling, because the spelling is sufficient to give the word exact coordinates on a concept graph of some sort. I thought about this approach some time ago, but was never able to find a non-arbitrary concept graph to use, or a system of word formation that didn’t create overly long or unpronounceable words.
I was originally thinking about including non-ascii characters, but eventually compromised on retaining English capitals instead. The biggest problem that any conlang faces is getting people to use it, and anything that makes that more difficult, such as requiring changes to the standard American keyboard, needs to be avoided unless it’s absolutely necessary.
I have a number of evidential categories available for use, as well as some relating to certainty, which I view as a separate issue (source versus certainty). But I hadn’t put any thought into making their use mandatory. There are certainly advantages to making it impossible to hide information by making the inclusion of some information carrying categories necessary. But it seems to me that not all possible information is going to be relevant to all possible statements or circumstances, and that forcing everyone to always include evidentials, even when they aren’t relevant, will carry a high price. There are probably aspects of speech other than evidentials that it would be advantageous to include in some circumstances. If the grammar requires that they all be included in every statement, then every statement will be overcrowded with irrelevant add-ons. Also, there’s the problem of enforcement. If, for example, you require that each statement end with an evidential, then what will stop irritated users from simply omitting it? If you create a system of grammar such that each of the add-ons must, unavoidably, be merged into the words, perhaps by some mechanism similar to verb conjugation, then how many people would volunteer to use such an inconveniently complex language? In order to be successful, a constructed language must be designed such that many people will want to use it. Only a few have reached that peak, such as Esperanto, and Klingon.