You are correct on both counts. The usual right hand piano sign, by definition, indicates that intervals are to be read downward, so even if you include the TN at the front of the volume, it's wise to use the special right hand sign for situations where intervals must be read upward.
Your alignment factor will become the first musical signs in the measure (or the word sign indicators if they appear in both hands - I can't recall how the example you are describing looks at the moment). There may be blank spaces that look awkward after the LH sign, but that can't be avoided.
All the best,