Except Christian theology has always seen sex in marriage as undefiling, and marriage as providing the legitimate outlet for sexual urges: "it is better to marry than to burn." East or West, the understanding had *always* been that virginity and continence were the perfection to strive for, but - if one was not strong enough to gain salvation in virginity, it was better to marry than to fornicate. Sex inside marriage is not fornication - fornication in marriage only comes from adultery (ie, 'alienation of affection'.)
This Pauline theory about sexuality and marriage was likewise based on a view of marriage based on property rights, illustrating this he also said, 'The wife hath not power of her own body, but the husband: and likewise also the husband hath not power of his own body, but the wife.' Now while Paul was somewhat revolutionary in extending the understanding of property rights within marriage to be mutual property rights (not merely rights of the husband), he still was solidly within the paradigm of marriage being an element of property and contract law.
I am not, by any means, the first to take issue with this understanding of marriage, Chrysostom spoke quite strongly against it and argued that sex was not even a legitimate reason, to say nothing of being a primary reason, for marriage in his treatise 'On Virginity.' Now, of course, my views and Chrysostom's views differ substantially on this issue, his goal was to discourage marriage period, whereas I have no intent to discourage it, but only to seek to insure that it is viewed in the proper context.
Furthermore, the eastern tradition is not nearly as aligned with your position as you believe it to be, such ideas as consummation being necessary to finalize a marriage is purely a popish invention, strongly rejected by eastern canonists. As I said above, Chrysostom rejected the notion that sexuality was in any way a central aspect of marriage. And numerous other saints would hgave agreed with him, including the Cappadocians...I would give more specific references but all my books are in boxes right now.
A liturgical fact that highlights this understanding is that traditionally the marriage crowns were not removed until one week after the wedding, and during this first week of marriage sexual intercourse was forbidden to the newly married couple. This is to say nothing of the long engagements that were generally required, generally lasting for years, and if the couple were to fornicate during this prolonged engagement, marriage between them was to be discouraged and they were to attempt to find other spouses (Basil 26).
Furthermore, there is precedence to call sex within marriage fornication, though in a slightly different context. When speaking of a third marriage Basil (4th Canon) says, 'As for those who are guilty of trigamy, they are excommunicated for the space of three years and often four years. For such a marriage is no longer to be called a marriage, but polygamy, or rather mitigated fornication.' So to insist that sex within a marriage formed under less than ideal circumstances is fornication is hardly a great deviation from the canonical tradition of the eastern Church.
Thus, since we have rejected the notion of property rights within marriage and have recognized the centrality of spiritual and non-sexual relationship (and insignificance of the sexual relationship), to insist that marriages based primarially on sex are fornication is hardly a great deviation from the customs of the Church...not that I feel bound to the same when considering matters of ethics. Sex for the purpose of fulfilling some animal desire rather than in the context of a close well-established relationship based on non-sexual love and attraction is fornication, plain and simple, regardless of what rituals you participated in or hoops you jumped through. Marriage does not legalize sex, and it only has meaning if the relationship in which sex would be morally acceptable already exists prior to the marriage itself.
The problem with late marriage (and 28 is late) is that it eats into the child-bearing years. One has far more energy in their 20s to deal with young children than in their 30s and 40s (I know this from experience!) Physically, pregnancy does far more damage to women if they are younger than 18 or older than 30. Damage to the chromosomes of the children increases to a great degree when the parents are over age 35.
So have one kid at 28 and one at 30...but my concerns with the world's gross overpopulation are another topic for discussion (though, if you do actually go and read Chrysostom's 'On Virginity,' you might find that he could have agreed with me

)
The reason why 28 *might* seem a good age is because our society has developed this artificial stage of life called 'adolescence' - roughly between 12 and 28. This societal construct of adolescence means that folk no longer behave like adults, nor take those responsibilities at an age that they are indeed capable of doing so - in their teens. In other words, teens and those in their 20s act like juveniles far longer than they should - and purely because it is expected of them.
There is a reason this developed in our society, we are no longer have an agricultural or even industrial economy...we have a professional economy. A college education is all but essential for success and economic stability, to say nothing of a secondary school education. Society has advanced, the intellectual requirements on it's members is far greater than it was at any other point in history; our society developed in the manner it did because it is tied to our economy, and just as participation in our economy requires greater rational abilities, so does proper participation in our society that is, in large part, derived from our economy.