Yeah, none of that is new and every bit of that clause is completely standard and nothing to be alarmed about. It does not give them rights over "anything on your computer", it's just necessary because their service allows you to embed files into documents you upload to their service.
That clause is necessary for them to offer Document Cloud, because it's required for, eg, "upload a PDF of a contract that embeds a JPG file containing your signature for use on the signature line". It's an extremely standard, boilerplate clause that is present in every ToS of every UGC site.
As far as these go, theirs is actually extremely well scoped: they have multiple limiter clauses many sites don't (2.1 is a reasonably strong limiter clause, but 4.2 has a *really* strong one, relatively speaking: "Solely for the purposes of operating or improving the Services and Software")
There are provisions in it I really don't like -- I am extremely not a fan of binding arbitration clauses and class action preclusions, both of which theirs has -- but it's getting harder and harder to find sites that don't include those.
The inclusion of the explicit disclaimer of nonassignment in 4.3, plus the scope limiters in 2.1 and 4.2, put it at a B+ on my scale of "user favorability", and I very famously do not grade on a curve.
I frequently wonder if binding arbitration and class action preclusions should just be illegal or if there's some important systemic reason to allow them.
I very much would like them to be, but they benefit companies (in that it's harder for customers to access legal recourse) so they've spread like wildfire. At least this one doesn't include the arbitration bundling provision places are adopting because people are DDoSing them with arb requests.
(My understanding is that they're also a little expensive for companies to actually use, compared to house counsel mimeographing "file your suit and we'll negotiate then" letters. A lot of users willing to just punish a firm monetarily can do so. It's a corporate bet that USUALLY works for them.)