Absolutely. Let's take 'em one at a time.
Integrity Checks. These can take a while. One strategy is to restore backups to a different server and run the DBCC CHECKDB on that. This way, doesn't matter how long it takes. If you aren't running integrity checks at all, you're going to have a giant problem if you ever get corruption, only to discover that your backups are corrupt too. I strongly suggest you read this article: http://www.sqlskills.com/BLOGS/PAUL...VLDB.aspx.
While 190 GB isn't a VLDB, the article is still relevant for you.
Update Statistics. First, make sure you have auto-update statistics turned on. I update stats manually with full scan periodically on selected tables. Even with auto update stats on, they can get out of date quickly when many inserts are performed -- particularly with identity and date columns. Bad stats will render a good index useless.
Reorg data and indexes. Depending on your situation, you can rebuild or reorg your fragmented indexes and data pages. I look for the most heavily fragmented indexes and rebuild them. This will usually reduce the number of reads performed by queries. Query optimization is almost ALL about reducing the # of reads. don't bother rebuilding small indexes ( less than a few thousand pages ). I won't touch 'em unless they are at least 25% fragmented and usually wait til much worse ( 45-50% )