You raised important questions about the problems of game mechanics. Some time ago I got interested in 2 particular problems and what was done to solve them: level ups after a while became a routine and boring fights. Both problems get worse by the end of the game. Below I will express my thoughts on this matter.
I think it is not such a big issue by itself, rather it reveals shortcomings in Feats and Force Powers Systems. New feats, force powers should add new opportunities, new tactics, new ways of interacting with the game world, the player should look forward to them. The level cap has been raised to 50; by the end of the game, the player can be over level 30. But there are not enough unique, interesting, useful feats and force powers that can change the game flow or be effectively used in new combat tactics.
There is not enough useful/interesting feats for player to acquire. Feats should add new opportunities, game experiences for the player. Instead, player can easily get all important feats by level 20 or so, and then just waste points on random, mostly useless stuff. Some of the new feats in TSL are okay, but most of them player acquire automatically. At the same time, the developers removed Heavy Weapons Feat and Implant Feat. Making implants dependent on Constitution attribute is a cool decision as it gives importance to this attribute that it lacked before, and Heavy Weapons Feat was redundant, but those feats had a significant impact on the gameplay in K1, so at least Heavy Weapons Feat deserve restoration.
I think that in an ideal situation, new feats should allow the player to receive new gameplay experience or at least be meaningful for player while not overpowered. There should be no situations when player acquired all good feats long before the end of the game.
As an example of “New gameplay experience”, the grenades aren’t that useful after beginning of the game. However, there is a mod called “Fumble! Grenades” that allow anyone who ever uses a grenade to have a chance at fumbling the throw. In addition, it restores Weapon Proficiency feat chain for grenades (makes them more powerful) and modifies it for fumbling.
There was also a mod “xc_grenades” by Xcom (if anyone have it, please, post a link or PM me) that made the Demolition skill to increase the damage of rockets and grenades. Together, these mods can change the way players view grenades, create new tactics based on grenades, be used in new builds.
The solution could be: adding a new feat chain to Feats which give 1 additional skill point to the player every second level and then every level after the feat is upgraded. In addition, TSL already has feats that make cross-class skills cost 1 skill point. The Jedi Guardian has more than enough feat points, so trading a few of them for skills can be an interesting alternative option. This idea may be contrary to D&D rules.
The Force Powers:
Some force powers are fundamentally broken. Heal, Speed, Force Storm – A player with any two of these force powers can become nearly unstoppable. And every player can use them without drawbacks: LS or DS, class, lightsaber/force form are not important, the cost of power is usually acceptable. Others are weak or rarely can be used effectively. It makes no sense to use most of the force powers, when it is easier and faster to spam Force Storm. Again, by level 20, the player has all good/interesting powers and is not motivated to try new ones. There is also lack of high-level force powers (even if they unnecessarily they can at least provide SOME motivation to level up in the late game). Almost all force powers become accessible by level 18.
All new feats, force powers, new tactics, improvements in mechanics won’t find usage in the game if every battle can be won by spamming Master Flurry or, even worse, a standard attack. There are several high difficulty mods that make enemies tougher and more dangerous, but I think that this is not enough to make the fights interesting.
Aside from the AI issues you mentioned, most fights are too similar to each other. There are not enough force users in the game and even they rarely use force powers (and again, most of the time they only use Life Drain), so some force powers/tactics are almost useless. The tactics of the enemies in the middle and the end of the game are the same. The most noticeable change between mid-level battles and level 50 battles is that enemies have more hp and can survive 1-2 Master Flurry. The bosses are indistinguishable from each other, the sith are bland and uninspired (most of them even don't have lightsabers), the various factions and groups of enemies differ only slightly from each other. There are not enough memorable situations (I can remember many more interesting fights in K1).
There are many types of damage in TSL, enemies could use different weapons types in various regions, parts of the game, then the player will be motivated to try certain armor and upgrades. But fire-based weapons mostly restricted to droids and cold and electrical damage is clearly underused.
I thought about mitigating these problems by using existing mods:
Heavy Weapons Feat Restoration
JC's Feat Fixes for K2
Fumble! Grenades + xc_grenades
Content Pack: Feats And Powers BY TamerBill
2) Force Powers
High-Level Force Powers
Force Power Lightsaber Floating by Darth333
3) Boring fights
Thematic Sith Lords - interesting mod that adds much-needed differentiation to fights against Sith Lords. I would like something similar to be done with other bosses and entire factions, sections of the game.
These mods are good at what they do (improve certain aspects), but I feel that a more complex solution focused on addressing all aspects of the problem, could potentially achieve more.
Is the problem that serious? As I recall high-tier upgrades cost several hundred components, and merchants can have crappy droid items in their inventory, so which upgrade T3 can do and when is partly a matter of luck. The point is, if T3 loses his status as a ‘skill master’ in the party, he‘ll become something like G0-T0, a character who has no gameplay purpose.
As for the merchants: the stocks of the merchants are random (from their lists of possible available items) and are generated only once when the player visits them, right? As a result, merchants often have poor inventory. Moreover, it makes no sense to buy equipment: standard items can be easily found in loot, and high-level items are in any case not available from merchants. So, the obvious choice is to allow merchants to sell non-unique high-tier items and update their inventory in similar manner to Suvam in K1 OR to add new end-game merchant with high-tier items to the game.
I can continue with other issues, but think that is big enough text for now. Thanks for reading!