It is difficult to discuss the possible inclusion of the themes of concern over being fairly judged and feeling ultimate trust in God in relation to this sonnet. One cannot argue that Milton does not feel this concern or that he does not feel this trust because the former is a common concern, since humans are all too fallible, while the latter is a foundational precept of Christian faith. Nonetheless, grammatical analysis cannot support the overt inclusion of these themes in this sonnet. One can perhaps interpretively read these themes into the poem, but a strong textual analytical argument cannot be made to support the interpretation.
The idea that Milton may feel dread (concern) about whether he might be judged unfairly comes from the mistaken analysis that this sonnet is a lament for Milton's loss of sight coupled with a complaint against the loss of his one talent. If the main idea of the poem is understood to be this complaint and lament, it is understandable that a reader would project an interpretation that Milton must therefore feel concern about his spiritual judgement. It is understandable that a reader would then also project courage onto the poet who dares to question God and a degree of ultimate trust that allows him to do so. This is especially so if "more bent" and "fondly" are defined as "more inclined than previously" and "foolishly" rather than being defined accurately as "continuingly inclined as before" and "affectionately" ("fondly" defined as "foolish" was outdated for 200 years by the time Milton wrote this sonnet in, to him, modern diction).
... that one talent which is death to hide
Lodg'd with me useless, though my soul more bent
To serve therewith my Maker, and [to] present
My true account, lest he returning chide,
"Doth God exact day-labour, light denied?"
I fondly ask. ...
The themes in the quoted passage that are supported through an analysis of the grammar and of the sonnet structure are instead related to (1) God's demands in face of external constraints and (2) the desire to serve faithfully. The primary theme is lodged in the main point, which occupies the volta--or the turn from the position stated to the answer given--in line 7 (noting that Milton has inverted the Petrarchan structure and placed the sestet first and the octave last): [paraphrase] Does God demand that which cannot be give without allowing an alternative for service? ("Doth God exact day-labour, light denied?") An alternative is suggested in "day-labour," which implies an alternative, such as night-labour, where the loss of light (i.e., sight) is less material. That an alternative is suggested is confirmed in the octave response from Patience who says that they "also serve" who "stand and wait."
The secondary theme is expressed in the opening sestet and might be paraphrased: I have the continuing desire to serve and to present a faithful account of my talent in the face of obstacles. The elegance and compression of Milton's language makes a paraphrase awkward and clumsy by comparison, but the relevant clauses in prose would correctly read: When I consider ... [that] my soul is still inclined to serve my Maker [with my talent] and still inclined to present a sincere expression of my talent (so as not to give Him reason to scold me), I affectionately ask Him ...." To return to our opening argument, while it may be tempting to impose an interpretation emphasizing themes of a concern over judgement and ultimate trust, we do so at the loss of Milton's more important expressed themes: (1) how to faithfully proceed sincerely in the face of obstacles and (2) does God demand what cannot be given with no alternative provided? The answers to the questions Milton raises lie in lines 11 and 14:
(1) How to faithfully proceed?: "'... [they] who best / Bear his mild yoke, they serve him best.'" (10, 11)
(2) Does God demand without an alternative given?: "'They also serve who only stand and wait.'" (14)