No, the problem with my analysis is that it disagrees with your fanboy viewpoint.
It may disagree with my fanboy viewpoint, but that's not why it's wrong.
I am not arguing that Esperanto is not grammatically easier than Interlingua on paper.
I am saying that writing Esperanto is not necessarily easier FOR EVERYONE than writing Interlingua.
And you're saying this from the position of someone who has tried learning neither language.
Besides, I could argue that syntactically easier languages require more and more symbols to convey the same amount of information of syntactically more complex languages.
And you'd be wrong -- that's a complete non-sequitur. Much of the "information" that syntactically complex languages convey is grammatical, not semantic, and often superfluous. Take conjugation, for example. In French you have je suis, tu es, il est, elle est, nous sommes, vous êtes, ils sont, and elles sont. In Arabic it's even more complicated. In English you have just am, is and are. In Esperanto you have just one conjugation, with exactly 
zero ambiguity. Why? Because language works that way.
The amount of memorizing required for being able to convey the same detail of information in every language is probably identical.
No it isn't! Have you ever 
tried learning a language?!
The easier the vocabulary and grammar are, the more you have to rely on idiomatic expressions to express details that in a more complex language could be exposed by using complex tenses/declensions/synonyms, etcetera...
Again, you make such patently false claims that you would 
know are ridiculous if you had spent just a week trying to learn Esperanto (it helps to have tried learning other languages so you could compare.) Idiomatic expressions, while they do exist in Esperanto (it's a living language, after all), are not that common, and due to the design of the language are 
never necessary to express what you want to say. You're making the completely unfounded assumption that grammatical complexity carries with it semantic complexity, when this is very often not the case. For example, it would take you twice as many words to say "Ni biciklos urben" (We will go to the city by bike) in Arabic, a much, much more grammatically complex language, and almost THRICE as many words to express the same idea in English. 
And it requires grasping fewer linguistic concepts to express in Esperanto. Of course, this is only the tip of the ice-berg -- every DAY I see an Esperanto word, that due to Esperanto's unique system of morphology, astounds me with its expressive terseness.
If you happen to also know computer languages, you should know that Assembly is, syntactically, a joke to learn compared to C++
Yet, for most algorithms, writing a solution in Assembly is a pain in the ass compared to C++.
You're right, but it's fallacious to propose that as a valid analogy. Assembly and C++ are different tools for different tasks. Assembly is good for its own thang, machine-level, memory-conscious tinkering, and C++ is good for its own thang, developing higher-level programs. But they're apples and oranges, unlike most languages. Take Python, for example -- its syntax is much, much, much easier than C++s, and for applications where you don't need the memory-management power of C++, it's often a better choice. If I asked you to write a prime-number generator, what language would you pick? 
Probably Python. Similarly, Esperanto, purely linguistically speaking, is often a better language for expressing complex thoughts than most national languages, because it was 
designed for optimum flexibility. And yes, there are languages that are even better than Esperanto in this domain, such as Ithkuil, but they tend to be conlangs too.
So, after having read the structure of both languages, I don't disagree that Esperanto grammar is way easier than Interlingua.
I disagree with you saying that it would require me less time to learn Esperanto than Interlingua for reaching a level of expression comparable to my native language (which is, syntactically, closer to Interlingua than Esperanto).
You reach that conclusion without even trying to learn either language. Consider this table:
Esperanto   Interlingua   English
sana   san   healthy
sano   sanitate   health
malsana   malade   sick, unhealthy
malsano   maladia   malady, illness, disease
malsanulejo   hospital   hospital
saniĝi   recovrar   to become healthy, recover
sanigi   curar   to make healthy, cure
malsaniĝi   cader malade   to become sick, fall ill
You need to know at least FIVE different roots to express all those concepts in Interlingua. You need to know just ONE root in Esperanto, and how the affixes work. Also, good luck keeping track of all the right forms of the words (which were chosen using a painstaking methodology centered on intelligibility, and not consistency or ease of learning.) Again, this reflects how Interlingua was designed for ease of understanding. I'm not saying Interlingua is a bad language. I'm not even saying that Esperanto is better. I'm just saying that you're judging Interlingua by Esperanto standards, and here it clearly falls short.
If you want to prove me wrong, go ahead and learn both Esperanto and Interlingua for two weeks each and tell us honestly which one you found easier to express yourself in. I promise I'll take your word for it.
Interlingua has the added bonus of being understood by hundreds of millions of people without having learned it.
That's true. And if that's something that appeals to you, then learn Interlingua.