Questions about Ethereum

I would like to know somethings about Ethereum…

Whats the maximum size of the block?

There’s a base time - a rate to new blocks -, like Bitcoin 10min/block?

And the Ethereum Mempool? It’s really crowded? I mean, if in Bitcoin blocks - that only deals with transactions - it was a problem sometimes (affecting the fees, for an example), handle with smart contracts as well must be huge… how does it work? Or Smart Contracts doesn’t pass through Mempool?

Is the propagation through the network as good as Bitcoin? Or it’s slower?

I was reading about Smart Contracts and something really attract my attention, the composability nature of it. It’s really interesting how it can be combined - like lego pieces -, but the security part it seems to be really scary too (the part the talks about the possibility of interaction of smart contracts - derived a new product seems to be really awesome but kinda fragile -)… i really would love to read more about it and to discuss more about this topic.

@filip @ivan @Maki