Hi - I wondered whether he might be a singleton? -Does he have a companion at the moment? If he is, then he is basically telling you all about his day, chattering as there is noone else to tell! - They are such interactive creatures, so this is a real treat for you to be given the entire days' events as seen by your guinea! As 70 says, if he was scared he wouldnt do any of the things you mention, he would hide, so he obviously feels comfortable to talk to you - in paired guineas, there is usually a loudmouth and a quieter, cant get a word in edgeways one, who usually has a resigned look! If he his on his own, he is expressing pleasure at having some company, so maybe you might think about a pal for him??! Otherwise, as long as he is involved with you and has plenty of attention, this communication is him accepting you as his companion.
GP's do seem to have a very wide range of noises and my boys are certainly a lot noisier than my current bunny. My previous bunny, however, had a much wider range of noises than my GP's. She had several aggressive noises, ranging from angry squeaks and grunts right through to a 'woof' (when she did that, we knew it was time to run and hide). She also had a lot of quieter, contented noises from little squeaks and mews to a kind of quacking sound when she got excited. Current bun is almost entirely silent, but then he lives with GP's who don't let him get a word in.
Awww if he's taking food and sitting still, he's fine. If he was scared he'd 'freeze' or try to hide in your sleeve.
Is it a constant background 'cooing' like a pidgeon rather than a 'wheek' ? A wheek is more of a "Food" ."I'm here" sort of noise.
Our GP1 (the big bolshy boar) does a very self-important shriek when he's lifted, then a noise like a mobile phone (soft ^doodle oodle do^) constantly. Even when he's happily tucked up under someones neck, he still prattles on.
GP2 is much quieter.No squeaks or wheeks but purrs or dove-cooing.