and it's also a discussion

All threads on forums are discussions. That's what forums are for. It's a matter of whether it's a discussion of the game in general, most often for topics that do not fit in any other category, or a discussion of a should-be feature, which goes in the suggestions.
Discussing a current feature, but not suggesting a fix would fit into General Discussion. Suggesting a new feature and comparing it to the current one would fit into Suggestions.

The Heat system is fine as it is. The Forge system is really what ought to be reworked, if it is to be kept at all.

Should we have remained with the Heat system, the most acceptable and stable change (and I wager a simple one at that) would be to increase the heat requirement for an item to level-up by a significant ratio. Not only would players be unrestricted by which tiers they need to venture in to upgrade their equipment and therefore be unhindered by a luck-based collectathon in order to progress, but Heat Amplifiers would find far more useage (the fundamental selling point of an Useable) and reason to be purchased in-game.

The Forge's advent and infamous development in implications shattered that very balance and created many infuriating problems as a result. I have no ill opinions on those who tolerate the system, but I insist strongly that the game should much rather be rid of its emprise entirely. Not the Forge system by itself, but its severe bottleneck influence on players' flow of progression. There must certainly be a way to repurpose the Forge in a way that will impeccably benefit the game, the players and the development team.

Honestly, normally I hate these repeat suggestions, but this forge system is so messed up any exposure will help. CHANGE IT.

I'm sorry, did I ask for the mist system? Maybe you'd like to put more words in my mouth.

We had a good system before, where heat translated directly into levels. The Spiral Knights team added radiants in order to slow progression so they could continue to add content before people maxed out everything they could. However, they corrected too far with the radiants and put a stranglehold that has lowered everyone's enjoyment. Instead, they should have just made lowered how much heat increased weapon levels. Not only would this allow players to level up weapons in a continuous manner, but it would push people to actually buy heat amplifiers, earning more money for the team.

[No name calling please]

Bringing any sort of "balance" to the heating & forging system would be a long & complicated process, no matter how they went about it. The first thing they should do is trash the portion of forging where you have to add Fire Crystals with every heat level, because having to add Fire Crystals level after level does nothing but waste excess generated heat, particularly when at any given time, any given item only needs a small amount of heat to bring it to the next level. An alternative solution would be to require users to collect the requisite amount of heat needed to bring an item to Lv. 10, and THEN require them to add their Fire Crystals, all at once, in order to fully unlock that item's Lv. 10 potential. This way, they're still able to heat an item, collect the Fire Crystals they need for it, and not have to worry about wasting heat or delaying their progress because they're not ready to "forge" yet.

A lot of people (including me) have also suggested that the number of Fire Crystals needed to fully bring out an item's potential should be lowered. This is something that I feel everyone can agree on, because there's no sense whatsoever in what amounts to practically throwing away Fire Crystals in the hopes that using less than the maximum amount per heat level will allow a player to advance their item(s) to the next heat level. With that in mind, the amount of Fire Crystals required for each item at each star level should be divided by three, and retain the "100% chance to forge" that the current maximum amount has. No more burning away Fire Crystals, no more "forge gambling" (other than the current random chance for double level-ups, heat bonuses, and Forge Prize Boxes)......just a simple, standard method of forging items that doesn't leave the player feeling needlessly cheated by some arbitrary "random failure".

Now, then.....I know you're all thinking that they can't just lower the Fire Crystal requirements without there being something to balance it, right? The simplest (and most obvious) way to do this is to dramatically increase the amount of heat that has to be collected per heat level.....for example, requiring the player to collect 8x, 12x, or maybe even 16x the amount of heat in order to bring each of their items to Lv. 10. Doing this would also have the added bonus of making Heat Amplifiers as useful as they were before the Forge system was introduced, especially if the benefits of the amplifiers were allowed to be stacked like the Krogmo Coin Boosters, albeit up to a maximum of three (i.e., 6x the amount of heat gained for as long as the amplifiers were active) at one time.

These are just suggestions, though......but as far as I'm concerned, this would be the best way to go about improving the now-current heating system.

It is still not a proper stand-in example for either challenge or replay value, nor does it provide any respectable or lasting benefits.

Increasing the heat curve to level up is a widely more acceptable alternative. I am quite certain the resulting complaints, should there be any, would be way too soft to come close to outweighing either the suggested alternative or the existing complaints over the Forge. Of course, the answer to the complaints over how longer it takes to level up via heat would simply be for the players to commit to extended playtime of their own and/or obtain then activate a Heat Amplifier.

Fully heating a weapon is the same as it was before the Battle Sprite Update, it was not hindered at all. However, leveling up requires the use of Fire Crystals with the corresponding star rank. Forging will never fail at the optimal setting (3x), but it thoroughly costly. Lesser settings (1x and 2x) use up far less Fire Crystals, but offer less bonuses and have a chance of causing a dud.

They can still manage plenty of income without the Forge, seeing as Fire Crystals in the Supply Depot are not tagged with desirable prices for most players. The global spending of CE on Fire Crystals is surely quite low compared to the majority of other commodities, there is much more for them to make money from. Besides, I am completely certain that lessening the incentive to buy them in favor of that of purchasing Heat Amplifiers would greatly benefit both the developers and the players.

On top of that, they could alternatively simply retain the Forge as it is without making it mandatory for weapons to level up. The Forge bonuses such as 25% Heat Gain and Double Level-Up would prove to be extremely valuable, especially moreso the higher the heat curve would be. The general idea is to make the Forge optional and not obligatory.