RAID 1 using Dell PERC H330, with no cache and no battery

We recently leased a dedicated server and found out that the server (Dell PowerEdge R230) has a Dell PERC H330 RAID controller. As we searched Dell's website, we found out that this controller does not have Cache Memory, does not have Write Back Cache and does not have Battery

Source: http://www.dell.com/support/article/ie/en/iedhs1/SLN292279/perc-poweredge-raid-controller-types-for-dell-servers?lang=EN

We intend to use this RAID controller for a RAID 1 (mirrored) configuration using 2 SATA hard disks.

1. Our main concern is that because Dell PERC H330 RAID controller does not have battery and cache this may be an issue regarding data safety and a risk factor for data corruption and data integrity problems.

2. Also, for increased safety and lesser risks, it is recommended to upgrade to Dell PERC H710 or Dell PERC H330 would be fine? Dell PERC 710 has Cache Memory 512MB NV and Flash Backed Cache for Write Back Cache.

3. Is the missing cache also an issue when rebuilding one drive due to one drive failure?