This is correct. In time expressions, until means ‘happening up to a particular point in time and then stopping’. In the example sentence, rather than a process that is happening up to a particular point in time, we have a deadline: you will only, presumably, raise any objections once, and you have to do that before 8 August. Here are some more examples, taken from the Macmillan English Dictionary:

Baker is expected to be here until the end of the week (=he will be here all week and will leave at the end of it).
I was employed by a manufacturing company until 1999 (=I was employed up to 1999 but not after it).
Up until now, everything in Katherine’s life has been taken care of for her (=all the time up to the present time).

I understand that according to British English usage, we say “There is an egg and two marbles on the table.” What I would like to know is whether is or are should be used if the sentence is rephrased as follows:

On the table is / are an egg and two marbles. 

It would be very odd to say On the table are an egg and two marbles because the plural verb sounds odd coming immediately before the singular noun 'an egg', even though the subject of the sentence is plural: 'an egg and two marbles'. But it doesn't sound great to say On the table is an egg and two marbles either, because of that plural subject. On the table is an egg is OK, if a bit odd, but then you have two marbles coming along and complicating matters. So you could invert it and say On the table are two marbles and an egg. That way you have a clearly plural verb with a clearly plural subject and everyone will be happy. It's still not very elegant, though.

In a sense these are false dilemmas, however. The point about writing is to communicate your ideas as clearly and unambiguously as possible. So if a structure sounds awkward or is ambiguous or inelegant, you should avoid it by expressing what you want to say in a different way. In this case, that would mean going for the first version of the sentence.

I would be grateful if you could let me know whether it is true that absolutely anxious is grammatically wrong. I have been told this by a friend of mine but on the Google website, I can find many examples of this phrase being used. Can I conclude that my friend is wrong?

In a sense you are both right, but your friend is more right. Absolutely anxious is not grammatically wrong, but it is an infrequent collocational choice, and as such sounds odd. As a teacher and lexicographer I would say that absolutely doesn’t collocate with anxious. Generally speaking, absolutely collocates with adjectives whose meaning is much stronger, such as terrible, disgusting and fantastic.

If you search on Google you will indeed find some citations – about 770 – for the chunk absolutely anxious. Compare this, however, with 226,000 for absolutely disgusting, 447,000 for absolutely terrible, 2,200,000 for absolutely fantastic, and you will see that 770 is not very many.

Collocational information is not by any means an absolute science or a set of rules; rather it is a statement of linguistic preferences, based on evidence of use. You can put any words you choose together – like Chomsky you can say that ideas sleep furiously if you want to. But the fact is that not many people do ever say that, and the pairing will sound odd (as it was intended to do).

Anxious tends to collocate with words like very, extremely and terribly; so if you want your English to sound natural, choose one of these. As for the choices of those who produced those 770 citations – well, from looking at the first few, I’d say that many of them were produced either by non-native speakers of English, or in rather specific technical contexts. This is a good reminder that what you find on the Web should always be treated with a measure of caution.