DevRain

I don't have any experience with Kore.ai but work a lot with Microsoft Bot Framework as a primary tool for building intelligent chatbots.

I would say you as developer will be responsible for (3) and (4) but you can use a big range of Azure services to develop what you need.

With Language Understanding service you can train NLP models based on your intents and entities, with QnA Maker you can build knowledge base to answer FAQ questions and conduct a small-talk (it calls "chit-chat"), with other Azure Cognitive Services you can add sentiment analysis, content moderator, linked entity extraction and other text/image/voice processing features.

With Azure Bot service you can publish chatbot across > 10 messengers and platforms.

If you are looking for a no-code or low-code solution for building chatbots, you can use Power Virtual Agents or Microsoft Bot Framework Composer. The difference is that Power Virtual Agents is a part of Power Platform which has additional licensing. Microsoft Bot Framework Composer does not have any connection to Power Platform or Microsoft 365 environment.

If you want to code everything from scratch and control all aspects of development, Microsoft Bot Framework is a choice.