This actually is quite safe: Ryanair is very reliable as an airline. Moreover you do actually have a plan B and C there: there is an Aer Lingus service arriving 09:30 into DUB and a BA service you could also get, arriving DUB 10:05, if FR somehow had a bad day. The BA service, via LHR, may well be available as an RFS even on the day of departure, worse case is a walk up fare, which won't be cheap but (a) unlikely to be needed and (b) still saves you buckets on a LHR originated fare.

Personally I would go for the earlier connection DUB to LHR, I'd be comfortable with that, but in advising other people I'd advocate the second connection. It physically takes about 30 minutes to get from T1 to T2 airside, even with that rather long hike along the elevated corridor in DUB. Passports takes slightly longer in T1 than T2, but nothing to worry about most of the time.

I'd leave it, seems safe to me. Just watch the departures from mid afternoon, and be prepared to leave work early to go via one of the many services between the London area and DUB in the unlikely event of trouble. Ryanair won't want people overnighted in hotels if there is an irrop, so you may be late, but you won't be sorry.

As a general comment, not targeted at anyone here, these sorts of fast turnaround services are not recommended to the risk adverse, overthinkers, worriers and those of a nervous disposition. There are other, better locations for turnaround apart from DUB (AMS, BRU, CPH, SVG, BGO, GOT) though of course they may not be quite so cheap. You get what you pay for.