Sql-server – Best High Availability Solution for SQL Server 2014

In order to redirect reporitng app or application with only read only queries you need to specify read only intent in application connection string (web.config or app.config in case client application is .NET)

The below is excerpts from SQL Server BOL

The application intent connection string property expresses the client application’s request to be directed either to a read-write or read-only version of an availability group database. To use read-only routing, a client must use an application intent of read-only in the connection string when connecting to the availability group listener. Without the read-only application intent, connections to the availability group listener are directed to the database on the primary replica."

Regarding your second question, if network throughput between two DC is OK you should be fine.

As long as any secondary replica is only solely used for DR (disaster recovery) and does not perform any work like read only request or backup you do not need to license it.

1. I would only use RAID 0 for the logs if you're okay with having reduced disaster recovery capability. You won't be able to make log tail backups in the event of a disk failure, and will only be able to restore to your most recent backup. However, this may be less of an issue if you're running Availability Groups, particularly with synchronous mirroring. You generally won't have any performance overhead for RAID 1 vs. a single non-RAID disk, but you will have better I/O performance with RAID 0 instead of RAID 1 for an equal number of disks.

2. Be aware that tempdb also has both data files and log files, and those could end up interfering with each other (performance wise) if placed on the same volume. You may want to consider foregoing the spare disk and using it for tempdb logs instead if performance still isn't acceptable. If your C: array is large enough, you might be able to get away with using it for on-disk backups, though you should probably partition it to prevent runaway backups from filling your OS disk.