The script looks just like your example script. With igv 2.3 it takes a few seconds for each variant, with igv 3.0 it takes minutes per variant.
new
genome hg19
load /mynormal.bam
load /mytumor.bam
snapshotDirectory /snaphots/
goto chr1:70503880-70503980
sort position
collapse
snapshot
goto chr1:114400333-114400433
sort position
collapse
snapshot
goto chr1:150482359-150482459
sort position
collapse
snapshot
goto chr1:176054897-176054997
sort position
collapse
snapshot
... repeat many times
$ /opt/installed/jdk1.8.0_111/bin/java -Xmx12g -jar /heskett/tools/IGV_3.0_beta/igv.jar --batch=bactchscript.igvsnapshot.txt
Running on 64 bit CentOS