No. I can't find data for a 1.1, but assuming we're talking a 90s or early 00s corsa then you're looking at 12 seconds for the 1.2.
Not true. My V70 was pretty poor on 0-62 time (over 8s), but with 470Nm of torque it could go 50-70 pretty devastatingly quickly. The reason that the 0-60 was poor was it was very badly traction-limited - it would spin/traction control/etc off the line, as well as be rather laggardly before it built some boost. None of these things occured on 50-70.
In terms of torque, power, weight and gearing it was very closely competitive to the E60 BMW 530d - a car with a 1.6 second faster 0-60 time because it had RWD traction. Physics says their rolling performance will be broadly comparable.
It's not about power - it's about Torque. A ~200bhp N/A petrol 4 pot (eg honda accord 2.4, 223Nm torque) will cope just fine while a 200bhp turbo diesel (eg my V70, 470Nm torque) can be a torque-steery mess.
Of course, there's more to it than just the power and torque outputs - the honda had a double-wishbone front suspension design that was distinctly grippier than the cheap ford Mac-strut front end on the Volvo
I do, however, agree that RWD feels much more "premium" to drive - the very absence of Torque-steer, the much more secure traction out of junctions and onto roundabouts, etc makes for a much nicer driving experience. The reasons for FWD are to do with packaging and cost (not only of components but production).
EVs are cheaper to produce in RWD, and suffer significantly from FWD torque effects (because you have INSTANT full torque available), so in the next few years you will see the "default" driven wheels switch back to RWD for all cars, even family hatchbacks. The first notable move on this is VW's MEB electric vehicle platform (the electric replacement for the MQB platform that currently underpins everything from a Seat Leon to the VW Atlas, Passat, Tiguan, etc), where RWD is the basic configuration (with AWD option).
Overall though, I think that you must judge the ES on its success. It has outsold the GS every year by huge margins. It appeals to the market that Lexus appeals to - a comfortable, cosseting vehicle, rather than trying to compete with BMW (as the GS has tried to do).