You forgot the Rainbow Left or whatever the Commies/Greenies call themselves. Also, Italia dei Valori is associated to the PD, just like Lega Nord is associated to PdL.
No idea, I would need to know more about each.
Popolo della Liberta=centre-right
Partito Democratico=centre-left
Lega Nord=Regionalism
Unione de Centro=Christian democracy, Social conservatism
Italia dei Valori=Populism, Centrism anti-corruption
lol. Italian parties have no ideology anymore. PdL is just Berlusconi's personal machine, which happens to be on the right and unites what is left of the First Republic's rightist parties (neo-fascist MSI, liberals, and so forth) but by far dominated by Forza Italia, Berlusconi's personalist party. PD is an unholy alliance of anybody opposed to Berlusconi and doesn't really have an ideology either, even though it happens to unite generally centre-left parties. As I said, it's an unholy alliance of former Communists, former Socialists, and former (conservative) Christian democrats. PD's pattern of support is also very much an unholy alliance. The UDC is what is left of the DC crooks who didn't join either coalition, Lega Nord originated as a northern protest party against DC and picked up votes of a lot of former DC but also PSI and PCI voters in the north, and Italia dei Valori is an ideologically diverse parties who existence is based solely on Berlusconi's rise to power. In a way, all Italian parties today are based around Berlusconi, either opposition or support to him. Either that or a personality cult.
Also remember that these are all corrupt.