Taking this a step further as I address the two other questions, if you reference that TR I mentioned before: NetApp and VMware Virtual Infrastructure 3 Best Practices
You will find that both of your questions are addressed in there (I highly advise reading this excellent document!)
As an example, on Page 8, it addresses iSCSI and FCP created luns as supporting resizing, but "Not in production"
With a follow-up mention on page 48 (Section 8.2 - Storage Growth Management) covering the steps to grow a VMFS Datastore
And then on page 15 (Section 4.2 - Storage Provisioning) it walks you through setting up VMware, igroups - and it goes on in additional depth as well.
Across the board I encourage you to check this Technical Document out, as it addresses not only the questions you're asking now, but likely ones you may wonder about going forward, as well as applying Best Practices and covering very important things (such as vmware vmdk alignment - Page 14, "Virtual Disk Starting Partition offsets" which often gets overlooked and when implemented up-front will allow you realize excellent benefits for your environment and future of your ESX deployment.
Look forward to more great questions and feedback from you Vijay!