Imho the Clans come closer to socialism then communism. They don't have a planned economy per se since they usually produce what they need in the needed quantity. Planned economy is more like a fixed plan without adjustments. The Foxes / Sharks are the exception since they produce more with which to bargain for other resources. But in essence the Clans are very socialistic since the collective is more important then the individual (here the exception are the Blood Spirits who allow their Clan members a great deal of individuality). And the general exception could be those Trueborn who earn a blood name who then serve as a kind of paragon to which the masses can aspire to.
Not really. The problem with 'on demand' production is when you need something you can't just shit out on demand-like foodstuffs. (See: Londerholm). The Clans are absolutely a command-based, central-planning economy-but thanks to space-magic and the FANTASY nature of Battletech, they didn't do what REAL systems configured like theirs have historically done (Starve to death and ossify after the first few years due to a lack of free market to parasitize off of).
They're NOT a Meritocracy, as your 'merit' is determined by your birth among the Clans, and even in the liberal ones, if you're not both a Trueborn, AND a warrior, you're a second class subject at the best of times. (citizens are allowed to take care of themselves, Subjects are ruled and cared for as the livestock they really are.)
the Clans are a caste-based SLAVE society, in which human beings are owned and traded like any other resource, the only modification being that in the case of the Clans, the ownership is collective as opposed to individual-the serfs are owned by the State, and traded as any other piece of the real-estate such as buildings or equipment, bought and sold, used as currency in gambling and so on.
Essentially the worst features of Feudalism and Socialism wrapped up in fancy sounding terminology integrated with Serfdom as practiced in the pre-revolutionary Russian Empire and integrated with 19th century ideas on Eugenics (that have subsequently been disproven in the real world).
That said, the closest model to the Clan system is Maoist communism as practiced by Pol Pot, but integrating the economics of Stalin and the ethics of that austrian painter who won some elections in Germany in the 1930s, but with a prettier sounding public relations campaign.
In short, not a place any sane person would actually WANT to live.