I left out two statements. Can you please consider them two?

1) As we are short of time (as the deadline is approaching), we urgently need to know if you would be interested in such a partnership.
2) If you have other proposals as to the topics to be dealt with within our research project, we are (more than??) pleased to consider them.
3) Is it a mistake to say "They have lived there since 1983 istead of they have been living there since 1983?)

Certainly! Here are the additional two statements included in the conversation:

1) "As we are short of time (as the deadline is approaching), we urgently need to know if you would be interested in such a partnership."

To address this statement, it appears that the speaker is expressing the need for a prompt response to their offer of a partnership or collaboration. The urgency is related to an approaching deadline. If you are responding to this statement, you could consider expressing your level of interest in the partnership and also mention if you would be able to provide a timely response. Additionally, if necessary, you may inquire about specific details or requirements related to the partnership.

2) "If you have other proposals as to the topics to be dealt with within our research project, we are (more than??) pleased to consider them."

In this statement, the speaker is inviting the listener to share any alternative proposals or suggestions regarding the topics to be included in their research project. If you are the intended recipient of this statement, you can respond by conveying your interest in the research project and expressing your willingness to contribute alternative topic proposals that may enhance the project. You might also seek clarification on any specific guidelines or preferences related to the proposals.

Now, moving on to the third question you've asked:

3) "Is it a mistake to say 'They have lived there since 1983' instead of 'they have been living there since 1983'?"

Both expressions convey slightly different meanings, so it is not necessarily a mistake to use either one. However, there is a nuance in their usage.

"They have lived there since 1983" suggests a period of residence that began in 1983 and continues up to the present moment. It emphasizes the ongoing nature of their living arrangement.

"They have been living there since 1983" also indicates a continuous residence from 1983 until now, but it places stronger emphasis on the ongoing action or activity of living. It highlights the duration and repetition of the action in the given time frame.

In most contexts, either phrasing would be acceptable. However, if you want to emphasize the continuous action of living in the specific time frame, "they have been living there since 1983" would be more appropriate.