I won’t presume that this is not some new thing that canon suggests as correct,

You should have presumed that, because that's what it is.

http://klingon.wiki/En/Instead

Canonical examples:

'awje' vItlhutlh; HIq vItlhutlh 'e' qa'
I drink root beer instead of liquor.

jIQam; jIba' 'e' qa'
I stand instead of sitting.

The 'e', and the second verb if a repeat, are often dropped in everyday speech. You'd be likely to hear these as:

'awje' vItlhutlh; HIq 'e' qa'
'awje' vItlhutlh; HIq qa'
jIQam; jIba' qa'

1. Making the second sentence of a Sentence As Object construction a dependent clause is uncommon, surfing the edge of complexity limits of the language. Add anything else in terms of complexity and communication might suffer.

I agree that turning an entire sentence-as-object construction into a subordinate clause heads toward too much complexity, but given the relative simplicity of the rest of it, I don't think this reaches the limit.

4. This comes really close to the Irrealis, which is problematic in Klingon. You are apparently trying to say, “If we WOULD replace swords with phasers, then we WOULD succeed.” Klingon doesn’t do “would”.

This isn't that kind of irrealis; this is a simple conditional. As far as irrealis is concerned, this is no different than bIjatlhHa'chugh, qaHoH If you say the wrong thing, I will kill you.

But Klingon does do irrealis, using a special construction for counterfactuals:

http://klingon.wiki/Word/Jal#More_Information

It is illustrated with a canonical example:

tlhIngan SoH net jalchugh, qagh DatIv
If you were a Klingon, you would enjoy gagh.

The difference between a conditional and a counterfactual is canonically illustrated thus:

Conditional:
qaghwIj DaSopchugh, qaHoH
If you eat my gagh, I'll kill you.

Counterfactual:
qaghwIj DaSop net jalchugh, qaHoH
If you were eating my gagh, I would kill you.

Notice how the counterfactual is not indicated morphologically in Klingon. It is expressed as a conditional sentence-as-object, plus an indicative sentence. Where English says would verb, Klingon just says verb. The would comes from the if one imagines that.

The fact that a standard grammatical construction, the counterfactual, consists of a subordinate sentence as object also casts doubt on claims that subordinate sentences as object are too complex to sustain.

-- 
SuStel
http://trimboli.name