Advice?

If I were you I would take the advice of your local bike shop, it looks a reasonably good bike for the money and you will have the assistance of the shop with getting the right size and making simple adjustments for you.

Weight won't make a lot of difference for riding unless you are racing or constantly going up hill. Once you are up to speed the weight is irrelevent and 12kg (26lbs) isn't that heavy anyway. I carry more than 12kg in rack and luggage on my daily commute and that is without the weight of the bike I use.

Buying a 2nd hand bike is only really suitable for people who know exactly what they need (size & components) and are confident enough to rebuild the bike if required.

Similar for buying online, you really need to know enough about size/components/fit/etc. to get a real bargain. You might be lucky but then again you might waste your money.

Imho first timers need the support of local bike shops and vise versa.

You haven't said how far your commute is, what terrain it covers, your general level of fitness (including your weight/height) so its difficult to give any meaningful advice.

For the record my commute is 15miles, climbs 200m and my commuting bike (with lock and rack but no panniers etc) weighs 14kg... so on the face of it that bike will suit.

I personally have some reservations about drop handle bars for commuting paricularly in traffic - my route rarely lets me get into speeds where going onto the drops would be beneficial and the more upright stance of the flat bar allows better visibility over the tops of cars. Also I find the longer wheelbase of the hybrid makes it more predicatable when filtering in traffic on bad road surfaces. By contrast my road bike is great for the open road but far to skittish to be safe in traffic IMHO.

At that price point, and staying with your LBS and that brand, have you looked at the Raleigh Urban 4? A more upright relaxed geometry for commuting and with slightly better components and a triple chainset rather than the compact, plus alloy rather than steel forks which will give a lighter steering feel - but the best advice is to get out there and ride a few different types before making any decision....

I don't even like the Allez personally, but if as said you can pick one up for the same kind of money, i'd probably go for it.
But IMLE of that specific bike, i'd have thought the Raleigh represented good VFM. If they're still made as well as my old Chimera, which had similar looks but a heavy cro-mo frame, that was a good strong bike that gave faithful service with all year round commuting I never regretted buying it.
I like the looks of it, but its bad enough trying to keep celeste bartape clean...with white you've no chance ..but thats a minor issue.