You don't have a "constructive eviction". The landlord has done nothing to prevent your use of the premises.
If you "claim" constructive eviction and leave you are guaranteed to be sued for breach of the lease and the landlord is virtually guaranteed to win. And you will not get your deposit or your build out costs.
With regard to the water damage from the next door tenant, your landlord has done nothing wrong and does not owe you a reduction in rent.
With regard to the bird poop, no heat, noise, you have to understand the legal elements of contract law. A breach of part of the contract doesn't necessarily give you the right to cancel the contract and walk away. On the contrary, you could simply have remedies available for the cure or compensation of the breaches. For that you will need to consult an attorney.
As for your loss of 15000 of business income, that's the responsibility of the other tenant, not the landlord. You, of course, can sue the tenant for the loss of income.
But you could have bought business income insurance.
- The right of the people
- to keep and bear arms,
- shall not be infringed.