I'm trying to use TYPO3 with SQL Server but I'm having several issues, especially when I install extensions like realurl, news and vhs. How is the status of use with this database? Is Doctrine integration fully (and I have made some mistakes) or we need to wait to use TYPO3 with SQL Server
The TYPO3 core moved to doctrine with version 8, MS SQL server works pretty well with a "naked" core. However, many extensions did not yet migrate (and release) versions which moved to the new doctrine based core API, but still rely on old TYPO3_DB which gives huge troubles with DBAL.
If you can, you should wait a bit, or contact (eg. via slack) / send patches to help extension authors with the doctrine migration. Actively telling ext authors that non-mysql instances are a topic can help, too.
This situation will eventually improve since the core removes TYPO3_DB support (and moved it to an external extension) with version 9. This adds some pressure onto extension authors to keep up with the doctrine migration, if they do not want to rely on an additional legacy extension.