When I first learned honorifics, I specifically remember my teacher saying that it is unnatural and kind of presumptuous to use ~て差し上げる as you are trying to be humble, but imply that you are, at the same time, doing a favour for someone in a higher position than you.
You might want to double check this one with a couple native speakers and get their input on it. Also be careful of who you ask; not all native speakers are as good with honorifics as they should be ^^ Asking an older person or a language teacher is best.
I'm hoping someone else can chime in on this, since I unfortunately don't currently have access to either of those types of Japanese people.
I wonder if that implication changes depending on the form you use: whether it's something you're stating in the past, or if it's an offer/invitation. (like a ましょう or ませんか).
