Some lightweight purses for clam like electrum?
As far I know there is no lightweight wallet for Clam, in the github I saw that someone was asking for a Electrum server for clam and they did some testing trying to create one but it seems like is not in the way to be implemented.
How many coins will I receive from 10,000 coins POS
Depend on multiple factors, someone can come and tell you x amount, but to calculate it properly you need to know if you are solo or pool staking, how many clams are staking at the same time as yours, how properly you is your ClamClient configured to stake efficiently if you're solo staking also if you let your ClamClient stake all the time 24/7 or partially.
Also, will I be able to import my "root key" as generated by Armory into the Clam wallet to redeem clams?
I don't use Armory but since the "root key" seems to be very specific for the Armory Wallet client and you will need to decrypt the wallet so the ClamClient can import it (not sure of that part), if you don't have lots of address you can try to export your private keys, i think that will give you a format that will be more ease for the ClamClient to import and redeem your Clams.
Here you can check 2 links if you want read more about you can do that.
how to obtain the private key of an armory wallet a post here in bitcointalk about how can obtain your private keysHow about this to see if it's worth spending any further time on CLAMs: ....
I was being a little facetious here, but after further thought, I believe you could actually dig your CLAMs. Create a raw transaction (on your air gapped, non internet computer) which sends your 'dug' CLAMs to a new address, then you transmit the transaction (which contains only public info that's going to go into the blockchain) on an internet connected machine.
I don't know if you are talking to me or to the OP, but we discussed previously about the "airgapped" offline system and with dooglus we confirmed that was viable to do it that way,
similar to your explanation , in the case of the OP this only have few workarounds if you don't want to use the ClamClient or anyone else service, check the code by yourself, trust code provided or forget about claiming your Clams. anyways thanks for your thoughts.