I am a little confused by what you are asking, due to the vagueness of your short hand sentences. Full disclosure, I do not have a Ranger, this is just educated guessing deduced from my experience playing a Shadowknight.
By "Swifty", do you mean
https://wiki.project1999.com/Swiftwind ?
By "Self-Hasted", do you mean the 40% worn haste from Swiftwind?
By "Grind mobs haste capped", are you suggesting that you now have 100% haste, when we were considering 40% worn haste exclusively in the first asterisked sentence?
I am going to make a few assumptions when answering these questions, based on what I believe you are asking:
You are asking about the DPS benefits (if any) of casting "High DPS" Ranger Spells while auto-attacking. You are not considering mana sustainability. I put quotes around "High DPS" because the aforementioned spells are high DPS for Rangers, not necessarily high DPS for spells in general. The asterisked sentences are different scenarios you imagine for auto-attacking, in terms of dual wield weapon load-outs and haste percentages.
If that is the case, this is my take:
Rangers are designed for auto-attacking. This is why you can get 90% self haste as a melee character relatively easy. Not to say Epic or Dark Cloak is easy, but it is more attainable by small/casual guilds than Velious raid gear.
1 hand weapons generally do not have a delay greater than 40. That means even with a blam stick or wurmslayer, your weapon delay is roughly 21 at worst when using 90% haste.
Due to the amount of auto-attacks you can output in the two second cast time for Call of Flame, that spell isn't worth casting at all. You will probably be doing roughly 200 damage per 2 seconds anyway, unless you are very unlucky with your damage and misses/dodges.
Calefaction probably does more damage than you can do in 2.5 seconds of auto-attacking, on average. Not to say you can't hit that number if you get lucky, but it is much less likely. Unfortunately, Calefaction has a 45 second recast time, so you cannot chain cast it. This makes it's use cases even more limited than they normally would be. If you could chain cast it, that would at least allow you to burn down a mob slightly faster than your auto-attack DPS.
Without the ability to chain cast, the only use case I could see for Calefaction when meleeing is in this scenario:
1. You are around 30-40% HP
2. The mob is around 25% HP
3. You want to get the mob under 20% ASAP, so the mob flees. You do not want them to stand their ground under 20% HP due to your own low HP. This means every second counts, and thus you cannot risk an unlucky dip in DPS, a series of unlucky misses/dodges, etc. The 450 damage from Calefaction would put the mob under 20% in 2.5 seconds guaranteed, assuming no resists or interrupts.
In raids, I can't see any use for these spells. Auto-attacking is much more useful on most raid mobs, due to their higher average levels and resistances.