There is a lot of points in your question which unless someone has the exact same setup as you - I don't think you will get the answers you are looking for.

I believe you should limit it by asking yourself: What is the ONE thing the MLM plugin I am looking for can do so that it achieves the maximum amount of result to my business by using it?

IMHO - it would be the ability to set commissions for the products you sell and award commissions to those affiliates that actually earn you sales. All other features, while nice, are ancillary features that from the perspective of the affiliate - don't really need in order to be successful.

In that regard - I would suggest https://affiliatewp.com/. When it comes to running affiliate programs on WP sites, it wins out as the best in my experience.

Hope this helps! Glad to assist any further if you need help.

I would suggest looking at ShareaSale as this does integrate with WordPress. This service supports multiple levels of payout and you can assign specific commission rates to individual affiliates as needed.

I've been an affiliate and merchant with ShareaSale for years and I've been very happy with their ability to manage the programs, payouts, and taxation.

Shareasale - https://goo.gl/hCZceg

I'm going to agree with Taylor on this, that your question includes many incredibly specific questions that most people won't have experience with.

That said, I also agree that AffiliateWP (https://affiliatewp.com/) is your best option for offering multi-level affiliate commissions as well as different commissions on varying products, all within each user's WordPress profile.

As long as you sell your products through one of the many services they integrate with (http://docs.affiliatewp.com/category/75-integrations), you will be able to accurately track all the data you need and automate affiliate payments at many different levels.

After going through your questions, I feel Epixel MLM Affiliate Management Plugin (https://www.epixelmlmsoftware.com/affiliate-mlm-plugin) might be a better option for you. Here’s why.

MLM Affiliate management plugin can manage your entire affiliate network, commission payments with customizable compensation plans that align with your goals. Features such as affiliate sales tracking and automation tools help streamline your operations.

Genealogy tree helps you visualize your entire network in one single tree view with basic details of all your affiliates. It can also equip your affiliates with a replicated website which is an individual website which can be leveraged for product promotions.

About your concern on commission percentages for different product types and categories, with an MLM affiliate management plugin you can seamlessly customize and manage commissions for different products and affiliates.

Also, the MLM Affiliate Management Plugin supports all popular open source platforms including WP Shopify, WooCommerce, OpenCart, etc. Social media integration available in the plugin can help you streamline your reward efforts on the platforms into your affiliate MLM system.

Additionally, You can integrate any compensation plan at any point to adapt to the changing business needs.

Depending on your goals and desired features, you can choose the best WordPress plugin for your multi-level affiliate marketing business, or "liaison" program as you may call it. Based on your description, here are some possibilities to think about:
Leading candidates for multi-tier marketing:
Strong multi-level capabilities are provided by AffiliateWP, a well-known plugin that lets you specify commission structures up to three layers deep. It offers accurate referral tracking, smooth integration with WooCommerce and other platforms, and analytical reporting.
WordPress Affiliate Manager: WP Affiliate Manager is a good alternative that offers multi-level capabilities and dashboards that are easy to use for both you and your affiliates. It has tools for tracking coupons, compensation systems that may be customized, and comprehensive reporting.
The Ultimate Affiliate Pro plugin is a premium tool intended for intricate affiliate networks. With its adaptable commission structures, customisable awards for high performers, and sophisticated reporting with real-time insights, it shines in multi-level management.

Plugins for general affiliate marketing that are versatile:
SliceWP: Well-known for its adaptability, SliceWP enables you to design any kind of affiliate scheme, including hierarchical models. It includes features like tracking coupons, personalized registration forms, and automated payouts, and it interfaces with other platforms.
Post Affiliate Pro: With its powerful tracking, multi-level functionality, and ample customization possibilities, this premium solution serves huge affiliate networks. It works with numerous marketing platforms and is capable of handling intricate commission schemes.
Thinking about the framework of your "liaison" program:

Pretty Links: Use Pretty Links to effectively manage and disguise affiliate links. In order to maximize conversion rates, it may even rotate various affiliate links, track clicks, and automatically shorten and brand your links.
EasyAzon: If your main source of revenue is Amazon products, EasyAzon makes managing affiliate links and product display on your WordPress website easier. It offers tracking capabilities, automates link updates, and interfaces with Amazon's Product Advertising API.
Bonus suggestion:
ReferralCandy is a WooCommerce plugin that specializes in referral schemes that reward recommendations made by other users. It features social media sharing buttons, gamification components, and easily configurable referral benefits, all of which link with WooCommerce.
The ideal plugin ultimately depends on your unique requirements.
Here are a few more things to think about:
Budget: While there are free plugins available, the features and capabilities of paid solutions are frequently greater.
User base and traffic: Pick a plugin that can grow along with the expansion of your program.
Technical proficiency: Take into account how at ease you are installing and configuring plugins.
Verify the plugin's compatibility with the platforms and tools you already use.
Support: Select a plugin that offers dependable help in case you require it.
With this knowledge, hopefully you will be able to select the ideal WordPress plugin for your "liaison" program. Don't forget to do extensive research on each choice and take your unique needs into account before choosing one.