Just curious, are there any obscure rules that prevent affixes like -in- and -et- etc being used in a non-suffix position? I will give examples to explain my query:

Let's say we want to say girl:
we'd get 'knab' and 'in' and we have 'knabin-o'
but perhaps we could go 'knab' and 'in' and have 'inknabo'
or 'ina knabo'? (with the distinction between possessing feminine gender and feminine tendencies being shown using 'em', e.g. inema knabo))

Similarly, that could be done with 'et' (dometo, etdomo/et domo), but would it be possible under the current grammar laws of Esperanto?

The reason I ask this is because normally one tries to stick all adjectives on the same side of a noun, but in the phrase 'eta knabino' it could be seen as having an adjective on both sides of the noun (eta - knabo - ina). Or in this case 'knab-' an adjective component, e.g. knaba - ino?

This isn't really something that's bothering me too much, but I'm just trying to think of new intuitive ways to speak and use Esperanto while sticking to the current rules and regulations.

(also, could I just ditch the use of 'granda' in favour of 'ega' or are there different implications?)

"etknabo" would be to me as correct as 'belsono' or 'rozkoloro'. I think it's just out of tradition for suffixes to be placed on the "right" side of a noun, unless they are employed as nouns; e.g. 'miaj etuloj' (my little darlings) is perfectly accepted and in some contexts it could be preferred over other forms like for instance 'karuletoj' (which makes me think about the very funny word 'amuleto'...).

About "ega": personally, the way I learned it, it confers a nuance of extremeness, bordering on the disproportioned; thus it would be (quite) different from 'granda'. The spoken language however tends to treat them in the same way and from what I can tell (which is very little as of late) this tendency is slowly winning over. In my head an "ideal" domego is an impossibly huge mansion with thousands of rooms. My interpretation might still be wrong, however.

ceigered:..I'm just trying to think of new intuitive ways to speak and use Esperanto..

You might enjoy reading what Claude Piron has to say about "morphemes". Here and here are a couple of articles.
This one is defending Esperanto (morphemes are mentioned in section E4).

Dankon mnlg for your input and info about 'ega', what you said sounded like what I had thought so I guess I might stick to using granda and ega like I have until now

Cheers Miland for that interesting set of links. I like the way he compared Esperanto to Chinese. And that's actually why I brought this up, 'coz in Chinese the 'adjective' component comes before the 'noun' component (or what we think of as the original noun before modification), e.g.:

Bovino = cow (bov (domesticated ox) + in (fe-))
母牛 (muniu) = cow (mu (female) + niu (ox))

My idea is that we could do the same in EO, so that in + bov go in the same order as their Chinese counterparts, and then if one wanted they could translate on a nearly word-for-word basis (well at least more word-for-word than English). Only then Chinese verbs don't conjugate like EO ones, unless you start the rule breaking
wode muniu shi gongniu! (我的母牛是公牛！)
mia inbov' est' virbov'!