I've used coir pots which are similar. It's quite handy to be able to plant them straight into the ground without disturbing the roots, but the flip side is that they dry out more quickly so you have to be careful about watering.
It's not good to use peat anyway, but the problem with peat pots is that they need to be moist all the time, otherwise they become rock-hard and the roots can't grow through them, which is their whole justification.
Completely agree with Maud...keep them moist/wet - and don't use them for seedlings that don't like wet feet (chilli, peppers etc). The seeds of the things your proposing are all quite big, so easy to sow and good "do-ers" (as seedlings anyway).