In advanced English morphosyntax, aspectual geometry, and temporal-modal interactions, verb phrases exhibit rigorous distributional constraints governing tense selection and aspectual realization. Consider the following four advanced propositions regarding tenses and their correct usage: I. In non-count durative states or habitual predications situated in the past, the past continuous tense can be deployed to express persistent annoyance or iterative irritation when combined with frequency adverbs such as 'always' or 'continually' (e.g., *'During his tenure, the former director was always interfering in routine departmental matters'*), operating as a stylistic alternative to 'used to'. II. When a subordinate temporal clause introduced by 'since' denotes the starting point of an ongoing state or action continuing into the present, the verb within the 'since'-clause must obligatorily appear in the present perfect tense to maintain temporal concordance with a main clause in the simple past. III. In future time reference clauses governed by epistemic probability or conditional dependency, future continuous and future perfect constructions allow speakers to project viewpoint aspect onto an unachieved timeline, marking either an action in progress at a specific future moment or an event completed prior to a future landmark. IV. The historical present (using present tense forms to narrate past events) can be freely interspersed with past tense forms within a single continuous narrative register without causing aspectual dissonance or narrative incoherence, provided the temporal foregrounding and backgrounding shifts are clearly marked by adverbial adjuncts. Identify the option that correctly evaluates the grammatical, syntactic, and semantic validity of propositions I, II, III, and IV according to standard English grammar and Grammatical tense theory.