FWIW. Here's the other side of the coin ...
If there is a problem with an inexpensive bike like the TONINO it will probably be due to inadequate setup and lack of subsequent maintenance ...
[INDENT]The tires & tubes may-or-may-not be good for many miles ... cloth rim tape may be worth buying, but you could always cheap-out and strap the rims with packing tape ...
700x40 tires are usually pretty robust.
[/INDENT]BUT, based on the laments of some posters (in other threads), I'm not sure that bike shops do much more than remove the bikes from the box & slap the parts on the bike & take the customer's money. LBSes offer a free adjustment after 30 days because they often haven't gone over the bike to ensure that everything is good-to-go + the cables usually need to be adjusted.
Regardless, it takes MORE skill to be a machinist than to set up or maintain a bike ...
As a machinist, you should be able to do anything-and-everything that needs to be done ... including relacing/truing the rear wheel with a different hub if/when the desire strikes you.
Most of what you need to know is available at www.parktool.com + Sheldon Brown's Bicycle Glossary ... and, many other sites. PARK TOOL would like you/(everyone) to buy/use their tools, and the site is form of advertising as much as it is a source of useful information.
[INDENT]You can use generic tools for most of the maintenance which needs to be done on a bike ...
[/INDENT]Cassette/Freewheel tools, Cone Wrenches & BB tools are only available from bike shops (brick, mail order or on-line).
The threaded headset wrench is a bike tool, too.
A chain tool + crank puller are bike tools which you may eventually want to own.
The brand of the tool is not a guarantee of quality, but most Park Tools are well made ... some aren't.
I think that LIFU makes most of other tools ... again, the quality varies, but they are generally good with the obvious exceptions being the cone wrenches & headset wrenches which are made with a soft steel.
IMO, the best (based on cost & efficiency) wire cutter (i.e., stranded steel bicycle cable) are on the HARBOR FREIGHT pliers & dikes which have ORANGE handles -- a set of seven (!?!) costs less than $10 when they are on sale (which seems to happen every few months) ... about 2x as much when they aren't.
The difference between Shimano front derailleurs is mostly in the clamp ... so, a replacement front derailleur is mostly cosmetic unless you change the number of cogs in the rear -- the front derailleur should be matched to the chain that is used ... the chain is chosen based on the cog spacing. The really inexpensive Shimano front derailleurs have a cruder parallelogram mechanism, but the difference in actual functionality will be minimal.
While the particular Shimano rear derailleur on the bike is one of the few which you would not want to buy as a replacement, it will probably last longer than you would like as long as you don't abuse it ... that is, grease & oil, as necessary. The OEM derailleur can be replaced with 90% of the rear derailleurs which Shimano makes -- despite what some people continue to misinform, the 10-speed Shimano rear derailleur does not have the same geometry as the 8-/9-speed Shimano rear derailleur ...
Without seeing a 'frame geometry chart', I reckon the 20" frame will probably be a best-fit for someone between 5'6" & 5'9", but it will be okay for someone who is shorter ... and, the larger 22" frame will possibly be a best-fit for someone between 5'8" & 5'11", but will be okay for someone who is taller.
So, while you may be able to get a USED bike which will probably have better components/etc. for the same money, I say that if 'I' had a limited budget (and, time constraints) + the skill to work on the bike(s) [which I happen to have AND which you should be able to master in a minimum amount of time] then I would not dismiss the Tonino Lamborghini Leggenda bike.
[INDENT]I'm 5'9" and would probably get the smaller 20" frame because I presume it has a 56cm (virtual) top tube [Flat Bar bikes tend to have proportionally longer top tubes ... I would prefer that the frame I ride have a top tube which is between 54.5cm & 56cm, but I can adjust a frame which is slightly shorter or longer to fit me by changing the stem length], and I presume the 22" frame might have a 58cm top tube ...
If I got a Tonino then I would eventually replace the handlebars with Drop bars + some 10-speed (non-QS!)Campagnolo shifters + cantilever brake calipers and a possibly a Road crank.
[/INDENT]You should not expect the saddles to be perfect for either you or your girl friend ... that's true with the saddle on most off-the-peg bikes.
BTW. Lubing the cables will go a LONG WAY toward enhancing the performance of the derailleurs & brakes.